TryBuildCalcArtificial Grass / Synthetic Turf Calculator (Strip Layout, Base, Infill, Seams & Fixings)
Plan artificial grass as real strips off a fixed-width roll, and get the full materials list.
🕒 Last updated: September 24, 2026
Inputs
Lawn Areas
Applies to every dimension on this form — lawn sizes in feet, and pile height, base depth and fastener spacing in inches. Switching converts the figures already entered rather than reinterpreting them.
ℹ️Sets a sensible starting point for the pile height, the infill type and rate, and the base depth — all of which you can then change. On a hard surface it also switches the whole installation to a bonded one, because there is nothing to nail into.
The default case: a decorative or lightly-used lawn. Published guidance puts residential infill at roughly 1-2 lb/sq ft, and a base at 3-4 in of compacted aggregate; 4 in is used here as the safer starting figure.
Area List
Add a row per rectangle. An L-shaped or curved lawn is best entered as the two or three rectangles it breaks into, measured to the widest point of each — that is how the turf gets cut anyway.
Area 1
Turf & Strip Layout
ℹ️The most important figure on this form. Turf is cut to length off a roll of fixed width, so the width decides how many strips your lawn needs and how much you pay for turf you cannot use. Check the actual roll width with your supplier before ordering.
ℹ️Most suppliers cut to length, so you pay for the linear metres or feet you need. Some sell full rolls only, in which case the order rounds up to whole rolls and the leftover is yours.
ℹ️Synthetic grass blades lean one way down the roll, so every strip in one continuous area must run the same way or the joint reads as a change of shade. That makes the running direction a single decision for the whole area — and it can change how much turf you buy by tens of percent.
Works out both directions for every area and uses the cheaper one, then tells you what the other would have cost. On an area whose width sits just over a roll width this is frequently a 15-30% difference in turf bought.
ℹ️The blade length. It sets how much infill is needed to hold the blades up, and it adds to the build-up depth you have to excavate for so the finished lawn sits flush with its edging.
ℹ️Spare length left at each end of every strip so it can be trimmed square to the edge. Added to both ends of each strip. Enter 0 to cut every strip exactly to length with nothing in hand.
ℹ️Extra on top of the strip layout, for trimming to curves, cutting around a tree or a manhole, and the piece that gets cut wrong. This is separate from the roll-width waste, which the layout already works out exactly — around 5% suits a simple rectangular lawn, 10% one with obstacles and curves.
When several areas each end in a narrow strip, those narrow pieces can be cut side by side out of one length of roll instead of one length each — they all still run with the pile, so it is a legitimate cut rather than a rotated offcut. Leave this off to keep each area on its own strips, which is simpler on site and harder to get wrong; turn it on to get the shared cut list and a smaller order.
Ground Preparation
A graded blend of crushed rock and fines — the same material used under roads. The default all-purpose choice: the fines let it lock up hard under a compactor while the coarse fraction carries the load.
ℹ️The depth AFTER compaction — the finished thickness under the turf. Published guidance puts a residential turf base at 3-4 in (75-100 mm), deeper for pets, heavy rain or vehicle loads.
ℹ️How much of its loose volume the aggregate loses under the compactor, typically 15-20%. The order is worked out by DIVIDING by what is left, not multiplying by the loss — at 20% you need 25% more loose material, not 20%.
ℹ️A thin fine layer screeded over the coarse base, because a graded sub-base cannot be levelled to the flatness a turf surface wants. Usually 0.5-1.5 in (12-40 mm). Its depth counts toward the excavation as well.
The usual position for a weed membrane: it blocks light so nothing germinates in the base, and it sits where you can still pin it down through the turf's fasteners.
ℹ️Membrane strips have to overlap rather than butt, or weeds find the joint. The overlap comes off each strip's effective width, so a 6 ft roll lapped 6 in covers 5.5 ft — which is why dividing the lawn area by the roll area comes up short.
Infill
ℹ️Infill weighs the turf down, holds the blades upright, shields the backing from UV and carries heat away. It is also the heaviest thing in the order by a wide margin, so it is bought by weight.
The default, and the cheapest by a distance. Rounded, kiln-dried grades flow between the blades instead of bridging; a sharp or unwashed sand packs and holds water. Published rates run about 1-2 lb/sq ft for a short residential pile and 2-3 lb/sq ft for a 1-2 in pile. Typical rate: 1-3 lb/sq ft.
ℹ️How much infill goes down per unit of lawn. Always check the turf manufacturer's own figure for your pile height — infill should sit in the bottom of the pile supporting the blades, not bury them. The result flags a rate that would do either.
Seams & Fixing
ℹ️The seam quantities come straight out of the strip layout, because a seam is exactly where two strips meet. If every area fits inside one roll width there are no seams at all and none of this is needed.
The standard, strongest method: 12 in wide tape run under the joint, adhesive troweled or gunned onto it, the two turf edges dropped on and weighted. Nothing penetrates the turf face, so the seam stays invisible.
5 in to 6 in galvanised or bright common nails (40D-60D) driven through the turf backing into the compacted base. The standard method wherever there is a base to nail into.
ℹ️The edge is where turf lifts, so this is the spacing that matters. Published guidance puts it at every 3-6 in (75-150 mm), tightening toward 3 in on an exposed edge. Counted fence-post style: one at each end of every run as well as those between.
ℹ️Most residential lawns are fastened only at the perimeter and seams, because the infill weight is what holds the middle down. A grid through the field is used on pet runs, play areas and anywhere the turf gets pulled at.
ℹ️Seam adhesive is quoted by the LINEAR foot of 12 in tape, not by area. A 5 gallon bucket covers roughly 250 linear ft, a 1 gallon pail about 50, and a 29 oz cartridge about 13.
Bends to a curve, which is what makes it the usual choice for a shaped lawn. Staked at roughly 3 ft centres.
Cost Estimation
Artificial Grass to Order
64.1 ft
19.5 m off a 15 ft (4.57 m) wide roll
Turf Area Bought
960.7 sq ft
89.3 m² / 106.8 sq yd, to cover 640 sq ft of lawn
32 ft x 20 ft lawn — 3 strips, 2 seams
40 ft (12.2 m) of seam to join, and 104 ft (31.7 m) of perimeter to fix down.
Strips run along the width: 3 strips of 20.33 ft off a 15 ft wide roll.
The last strip only needs 2 ft of its 15 ft width, leaving a 13 ft x 20.33 ft offcut. You still buy the whole width, because the pile has to run the same way in every strip.
Where the Extra Turf Goes
| Lawn actually covered | 640 sq ft | 59.5 m² |
| Roll width bought but not covered Pure geometry: you buy whole roll widths, and the last is usually partial. The one component a layout change can remove. | +260 sq ft | 40.6% of the lawn |
| End trim at each strip end An allowance you set, not waste — spare length to cut square to the edge. | +15 sq ft | 915 sq ft running total |
| Cutting and fitting allowance (5%) For curves, obstacles and the piece that gets cut wrong. | +45.7 sq ft | - |
| Turf bought | 960.7 sq ft | 50.1% over the lawn area |
An area-based turf calculator reports only the last line as a flat 10% and misses the roll-width component entirely — which on this job alone is 260 sq ft.
Strip direction changes the order
Running the strips the other way round would have needed 55 sq ft more turf (5.1 m²). The cheaper direction was chosen for each area — set it out that way on site.
Ground Preparation
Excavate to: 6.75 in (17.1 cm) — 4 in of base plus 1 in of levelling course plus 1.5 in of turf and backing, so the finished lawn sits flush with its edging
Spoil to remove: 13.3 cu yd in the ground, bulking up to roughly 16-17.3 cu yd once dug
Class II road base / crushed aggregate base, compacted volume: 7.9 cu yd (213.3 cu ft / 6 m³)
Order loose (+20% compaction): 9.9 cu yd = 13.7 US tons / 12.5 tonnes
Decomposed granite / crusher fines levelling course: 2.5 cu yd loose (3.3 US tons / 3 tonnes)
The loose volume is the compacted volume DIVIDED by (1 - 20%), not multiplied by (1 + 20%). Multiplying gives 9.5 cu yd, which is short — a mistake that leaves you a fraction of a load light at the very end of the job. Aggregate density is taken as 1.39 US tons per cubic yard loose; confirm it with your own supplier, since it varies with grading and moisture.
Infill
Kiln-dried silica sand (rounded) at 1.5 lb/sq ft (7.32 kg/m²): 960 lb / 435 kg (0.5 US tons)
That is 20 x 50 lb bag, about 9.6 cu ft of material, sitting roughly 0.18 in deep — 12% of the 1.5 in pile
Spread over the 640 sq ft of lawn, not the 960.7 sq ft of roll bought — offcuts never get infilled. Volume is estimated from a typical loose density of 100 lb/cu ft for this material; the purchase figure is always the weight.
Seams, Fixings & Accessories
Seam tape: 1 x 12 in x 328 ft (100 m) roll for 40 ft of seam
Adhesive: 1 x 5 gallon bucket at 250 linear ft of seam per pack
Galvanised turf nails / spikes: 313 (2 packs of 250) — 313 around the perimeter at 4 in centres
Weed barrier: 1 roll of 6 ft x 300 ft — 120 ft of strip, over the base, directly under the turf
A 6 ft roll lapped 6 in covers only 5.5 ft per strip, which is why dividing the lawn area by the roll area comes up short — that method would have given 1 roll.
Bender board (flexible plastic or composite): 6 x 20 ft for 104 ft of perimeter, plus about 36 stakes
Assumptions Used
Each area is laid out as whole strips cut off a 15 ft wide roll, with every strip in an area running the same way, because synthetic grass blades lean one way down the roll and a rotated strip reads as a different shade of green. That is why a partial last strip still costs a full roll width, and why offcuts are never rotated to fit. Each area's running direction was chosen to buy the least turf, with less seam breaking a tie. Seam length is taken as the full length of every joint between strips, which is where the tape, adhesive and seam-fastener quantities come from. Base aggregate, infill and any barrier or shock pad are sized on the 640 sq ft of lawn actually covered; turf is sized and priced on the 960.7 sq ft of roll bought. Base aggregate is ordered loose, as the compacted volume divided by (1 - 20%), and converted to weight at a typical loose density rather than an exact one. Every whole-unit count — strips, rolls, bags, packs, boards — rounds up from unrounded values. This calculator estimates material quantity only. It does not design a drainage scheme, certify a playground fall height, assess subgrade bearing, or account for tree roots, service runs or existing structures.
Bill of Materials
Main material: 64 linear ft + recommended tools
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Bill of Materials
Main material: 64 linear ft + recommended tools
Computed quantities come from your own areas, roll width and material settings above; the consumables below are general recommendations, filtered to this installation — actual needs vary by product, ground conditions and site access.
For Your Job
Artificial grass
Base aggregate — Class II road base / crushed aggregate base
Levelling course — Decomposed granite / crusher fines
Weed barrier / geotextile
Infill — Kiln-dried silica sand (rounded)
Seam tape
Turf adhesive
Galvanised turf nails / spikes
Perimeter edging — Bender board (flexible plastic or composite)
General Tools & Consumables
Utility knife and plenty of spare blades
Chalk line or marking paint
Tape measure (long, 100 ft / 30 m)
Stiff broom, or a power broom for anything sizeable
Wheelbarrow
Gloves and knee pads
Groundwork & Base
Plate compactor (hire)
Spade, shovel and landscaping rake
Screed bar or straight timber, plus a level
Skip, grab lorry or spoil removal
Drainage aggregate, channel or French drain
Seaming
Notched trowel or caulking gun
Seam roller or weights (sandbags, boards)
Disposable gloves and a solvent wipe
Fixing Down
Claw hammer or rubber mallet
Carpet kicker or turf stretcher
Infill
Drop spreader
Plan drawn to the proportions of the dimensions entered, divided into the actual strips the layout needs; arrows show the pile direction every strip has to share, dashes mark the seams, and hatching marks roll width bought beyond the lawn edge. End trim at each strip end is included in the order but not drawn. Section layers are proportional to their real depths, with a minimum thickness so thin layers stay legible.
What Is an Artificial Grass Calculator?
An artificial grass calculator works out how much synthetic turf an area needs, and turns that into a materials list you can order from. It solves a problem that looks like simple area arithmetic and is not: artificial grass is not a bulk material sold by the square foot, it is a manufactured sheet of fixed width cut to length off a roll, and that changes the answer substantially.
This calculator is built for anyone actually buying the materials — homeowners pricing a DIY lawn, landscapers quoting an installation, contractors checking a supplier's take-off, and anyone working out whether a synthetic lawn is worth it before committing. You enter a row per area with its dimensions, choose the roll width you will be supplied, and it returns the strip layout, the linear feet or metres of roll to buy, the seam length, and the base aggregate, weed barrier, infill, seam tape, adhesive, fasteners and edging that go with it.
It differs from the usual online turf calculator in four ways that change the answer rather than the presentation. First, it plans real strips off a fixed-width roll instead of multiplying the area by a waste percentage — the difference on a lawn that sits awkwardly against the roll width can be 50% rather than 10%. Second, it respects the pile direction constraint: every strip in one area must run the same way, because a rotated strip reads as a different shade of green, which is precisely why offcuts cannot be turned to fit. Third, it compares both running directions and tells you which buys less turf, a saving no competitor tool surfaces. Fourth, it gets the compaction conversion the right way round — loose aggregate volume is the compacted volume divided by what compaction leaves, not multiplied by what it removes.
Everything downstream of the layout falls out of it. Seam tape and adhesive quantities come from the seam length, which only exists once you know how many strips there are. Infill and base are sized on the lawn area actually covered, never the roll area bought, because offcuts are never infilled. Fasteners are counted around each area's own perimeter at the spacing you set. The result is a bill of materials rather than a single square-footage figure.
Artificial Grass Formula & Method
Every figure is computed in feet, square feet, cubic feet and pounds, and converted only for display. Feet is the natural working unit because the governing quantity — roll width — is a fixed manufactured dimension, and because the layout is an integer count of those widths across a measured area.
Step 1 — Strip layout, per area
For strips running along dimension A, across dimension B:
strips = ROUNDUP( B / roll width )
strip length = A + 2 x end trim
roll length = strips x strip length
turf area = roll length x roll width
lawn area = A x B
seams = strips - 1
seam length = seams x A
width waste = (strips x roll width - B) x A
The ROUNDUP is the whole point. You buy whole roll widths, so a 16 ft wide lawn off a 15 ft roll takes two strips and you pay for the other 14 ft of the second strip. That is not a waste allowance, it is geometry — and it is reported separately from the cutting allowance for exactly that reason. Note that the seam runs the length of the AREA, not of the over-long strip.
Step 2 — Which way the strips run
Option 1: strips along the length
A = length, B = width
Option 2: strips along the width
A = width, B = length
Choose the option with the smaller turf area;
if equal, the one with less seam.
CONSTRAINT: every strip in one continuous area
must run the SAME way (pile direction).
Synthetic grass blades lean one way down the roll, so a strip laid at ninety degrees to its neighbour reads as a different shade of green from most angles — the same effect as nap on a carpet. That constraint is what makes the running direction a single decision for the whole area, and it is why the usual offcut-rotating tricks from tiling and flooring are unavailable here. On a lawn whose width sits just past a roll width, swapping the direction frequently changes the turf bought by 15-30%.
Step 3 — The whole job, and the allowances
roll length = sum over areas of
(strips x strip length x count)
order length = roll length x (1 + cutting% / 100)
order area = order length x roll width
whole rolls = ROUNDUP( order length / roll length )
Over-purchase, split into its three causes:
width waste — geometry, removable by layout
end trim — an allowance you set
cutting % — curves, obstacles, mistakes
Splitting the over-purchase matters because only the first component can be designed out. A single blended waste percentage hides the fact that a lawn a foot over a roll width is paying for a whole extra strip, which a small change to the layout would delete entirely. The cutting allowance is genuinely separate: around 5% for a simple rectangle, nearer 10% with curves and obstacles.
Step 4 — Base aggregate and excavation
compacted volume = lawn area x compacted depth
loose volume = compacted volume
-------------------------
(1 - compaction% / 100)
weight = loose volume x loose density
excavation depth = base depth
+ levelling course depth
+ pile height + backing
spoil (bulked) = in-situ volume x 1.20 to 1.30
The division is the part published turf calculators get backwards. At 20% compaction the loose volume needed is 25% more than the compacted volume, not 20% more — multiplying leaves the order about 4% short, which is enough to stop the job at the final lift. Excavation is the full build-up, not just the base: getting that wrong is the commonest reason a finished artificial lawn stands proud of its own edging. Dug soil bulks up, so size the skip on the bulked figure, not the hole.
Step 5 — Weed barrier, in overlapping strips
effective width = roll width - overlap
strips = ROUNDUP( area width / effective width )
length = strips x area length x layers
rolls = ROUNDUP( length / roll length )
layers = 2 for a separation layer below the base
AND a weed membrane above it
A membrane is also a fixed-width roll laid in strips, with one difference: the strips must overlap rather than butt, or weeds find the joint. So a 6 ft roll lapped 6 in contributes only 5.5 ft per strip, and dividing the lawn area by the roll's nominal area comes up short. Unlike turf, a membrane has no pile direction, so its strips are always run whichever way needs fewer of them.
Step 6 — Infill, seams and fixings
infill weight = LAWN area x rate (lb/sq ft)
infill bags = ROUNDUP( weight / bag weight )
infill depth = (weight / density) / lawn area
tape rolls = ROUNDUP( seam length / roll length )
adhesive = ROUNDUP( seam length / linear ft per pack )
or, glued down:
= ROUNDUP( area / sq ft per pack
+ perimeter / linear ft per pack )
perimeter fasteners = ROUNDUP( perimeter / spacing ) + 1
per area
field fasteners = ROUNDUP( area / spacing² )
edging pieces = ROUNDUP( perimeter / piece length )
Infill goes on the lawn area, never the roll area — offcuts are never infilled, and on a job with heavy layout waste the difference is a whole pallet. Adhesive is the one line with two different bases: a seam bead is quoted per linear foot of 12 in tape, a full glue-down per square foot of surface, and using one for the other is out by an order of magnitude. Perimeter fasteners are counted fence-post style, one at each end of a run as well as those between, applied per area because each lawn is its own closed loop.
Worked Example
This example walks through your current inputs above, using the same steps as the Formula section.
Input Values Used
| Input | Value |
|---|---|
| Area 1 | 32 ft x 20 ft (9.75 m x 6.1 m) |
| Application | Lawn / general landscaping |
| Roll Width | 15 ft (4.57 m) |
| Strip Direction | Whichever wastes less (recommended) |
| Pile Height | 1.5 in (3.8 cm) |
| Allowances | 2 in end trim per strip end, plus 5% for cutting |
| Base | Class II road base / crushed aggregate base, 4 in compacted, 20% compaction |
| Infill | Kiln-dried silica sand (rounded) at 1.5 lb/sq ft (7.32 kg/m²) |
| Seam Method | Seam tape + turf adhesive |
Step 1 & 2 — Strip Layout, Both Directions
| Area | Calculation | Result |
|---|---|---|
| Area 1 | ROUNDUP(32 / 15) = 3 strips of 20 + 2 x 0.17 = 20.33 ftThe other way round: 2 strips, 970 sq ft of turf | 915 sq ft of roll, strips along the width last strip uses 2 ft of its 15 ft width |
| Whole job | 3 strips across 1 area | 61 ft of roll = 915 sq ft |
Step 3 — Turf to Order, and Where the Extra Goes
| Calculation | Result |
|---|---|
| Lawn actually covered | 640 sq ft (59.5 m²) |
| (3 strips x 15 ft of width) less the lawn width, over the run | +260 sq ft roll-width waste (40.6%) |
| 3 strips x 2 x 2 in of end trim x 15 ft | +15 sq ft end trim |
| 61 ft x (1 + 5% cutting allowance) | 64.1 ft of roll |
| Order | 64.1 linear ft (19.5 m) = 960.7 sq ft bought, 50.1% over the lawn |
Step 4 — Base Aggregate and Excavation
| Calculation | Result |
|---|---|
| 640 sq ft x 4 in / 12 | 213.3 cu ft compacted (7.9 cu yd) |
| 213.3 / (1 - 20%) | 9.9 cu yd loose to order multiplying instead of dividing would have given 9.5 cu yd — short |
| 266.7 cu ft x 103 lb/cu ft | 13.7 US tons (12.5 tonnes) |
| 640 sq ft x 1 in / 12, then / (1 - 20%) | 2.5 cu yd of decomposed granite / crusher fines (3.3 US tons) |
| 4 in base + 1 in levelling + 1.5 in pile + 0.25 in backing | excavate 6.75 in (17.1 cm) |
| Spoil, bulked 20-30% once dug | 16-17.3 cu yd to cart away |
Step 5 & 6 — Infill, Seams and Fixings
| Calculation | Result |
|---|---|
| 640 sq ft x 1.5 lb/sq ft | 960 lb (435 kg / 0.5 US tons) of kiln-dried silica sand (rounded) |
| ROUNDUP(960 / 50) | 20 x 50 lb bag |
| (960 lb / 100 lb/cu ft) / 640 sq ft | 0.18 in deep — 12% of the 1.5 in pile |
| 2 seams x their strip runs | 40 ft of seam (12.2 m) |
| ROUNDUP(40 / 328) | 1 x 12 in x 328 ft (100 m) roll |
| ROUNDUP(40 / 250) | 1 x 5 gallon bucket of adhesive |
| ROUNDUP(104 ft / 0.33 ft) + 1 per area | 313 galvanised turf nails / spikes — 2 packs of 250 |
| Strips at (6 - 0.5) = 5.5 ft effective width, then ROUNDUP(120 / 300) | 1 roll of barrier (120 ft of strip) |
| ROUNDUP(104 / 20) | 6 x 20 ft of bender board (flexible plastic or composite), about 36 stakes |
Figures above are rounded for display; the real quantities are always calculated from full, unrounded values.
Therefore, covering 640 sq ft of lawn (59.5 m²) takes 64.1 linear ft of 15 ft wide turf — 960.7 sq ft bought, 50.1% over the lawn area — laid as 3 strips with 2 seams, over 13.7 US tons of base, with 20 bags of infill.
Essential Checklist+−
Complete these critical checks before approving the work or proceeding to the next construction stage.
✓Measuring & Strip Layout Planning+-
- Actual roll width confirmed with the supplier before any quantity is worked out
- Pile direction decided for the whole lawn, and every strip planned to run that way
- Every area measured to its widest point in each direction, not its average
- Irregular and L-shaped areas broken into rectangles, each entered as its own row
✓Excavation & Sub-base+-
- Excavation depth set as the FULL build-up, so the finished turf sits flush with adjoining surfaces
- Subgrade cleared of organic material, roots and soft spots, then compacted before any aggregate goes down
- Base compacted in lifts of 1-2 in with a plate compactor, not dumped and compacted in one pass
- Aggregate ordered as LOOSE volume, worked out by dividing by what compaction leaves, not multiplying by what it removes
- Angular crushed aggregate with fines used, never rounded pea gravel
- Fall and drainage confirmed — the base shaped to shed water, and a drain added if there is nowhere for it to go
✓Laying & Seaming+-
- Turf rolled out and left to relax in the sun before any cutting or seaming
- Factory selvedge trimmed off both edges to be seamed, cutting between stitch rows from the back
- Seamed edges butted with a consistent hairline gap, never forced tight and never left open
- Seam tape centred under the joint, shiny side down, and the adhesive given its full cure before traffic
✓Infill & Fixing Down+-
- Perimeter fastened at close centres — the edge is where turf lifts
- Infill rate taken from the turf manufacturer's figure for that specific pile height, not a generic rule
- Infill applied in two or three passes with brushing between, not dumped in one go
- Over concrete, decking or a balcony, the turf BONDED rather than fastened, and the surface prepared for it
✓Drainage, Safety & Aftercare+-
- Drainage tested with water before the job is signed off
- For play areas, fall-height protection verified against the equipment — not assumed from the turf
Full QC Checklist+−
Verification checklist for an artificial grass installation — covering how the lawn was measured and the strips planned, excavation and sub-base preparation, laying and seaming the turf, infill and fixing, and drainage, safety and aftercare. Use the Essential Checklist for the critical checks before ordering, and expand to the Full QC Checklist for complete verification.
✓Measuring & Strip Layout Planning+-
- Actual roll width confirmed with the supplier before any quantity is worked out
- Pile direction decided for the whole lawn, and every strip planned to run that way
- Every area measured to its widest point in each direction, not its average
- Irregular and L-shaped areas broken into rectangles, each entered as its own row
- Both running directions compared before the layout is fixed
- Checked whether the lawn sits just over a whole roll width, while the design can still change
- Trees, manholes, service runs, posts and beds identified and allowed for in the cutting allowance
✓Excavation & Sub-base+-
- Excavation depth set as the FULL build-up, so the finished turf sits flush with adjoining surfaces
- Subgrade cleared of organic material, roots and soft spots, then compacted before any aggregate goes down
- Base compacted in lifts of 1-2 in with a plate compactor, not dumped and compacted in one pass
- Aggregate ordered as LOOSE volume, worked out by dividing by what compaction leaves, not multiplying by what it removes
- Angular crushed aggregate with fines used, never rounded pea gravel
- Fall and drainage confirmed — the base shaped to shed water, and a drain added if there is nowhere for it to go
- Fine levelling course screeded and rolled to a true surface before the turf goes on
- Weed membrane strips lapped, not butted, and the overlap allowed for in the quantity
✓Laying & Seaming+-
- Turf rolled out and left to relax in the sun before any cutting or seaming
- Factory selvedge trimmed off both edges to be seamed, cutting between stitch rows from the back
- Seamed edges butted with a consistent hairline gap, never forced tight and never left open
- Seam tape centred under the joint, shiny side down, and the adhesive given its full cure before traffic
- Seams positioned away from main traffic lines and prominent sightlines where the layout allows
- Turf stretched out flat and wrinkle-free before it is fixed at the perimeter
✓Infill & Fixing Down+-
- Perimeter fastened at close centres — the edge is where turf lifts
- Infill rate taken from the turf manufacturer's figure for that specific pile height, not a generic rule
- Infill applied in two or three passes with brushing between, not dumped in one go
- For pet areas, an odour-controlling infill specified rather than plain sand
- Over concrete, decking or a balcony, the turf BONDED rather than fastened, and the surface prepared for it
- Perimeter edge restrained by edging, a trenched board or an existing hard edge
- Every fastener driven flush and its head hidden in the pile
✓Drainage, Safety & Aftercare+-
- Drainage tested with water before the job is signed off
- For play areas, fall-height protection verified against the equipment — not assumed from the turf
- Surface temperature considered for the exposure, and shade or a cooling infill planned where it matters
- Manufacturer's warranty conditions read and the installation built to meet them
- All rolls checked as the same batch, or any batch change placed where it will not show
- Maintenance routine understood — brushing, debris removal and topping up infill
- Usable offcuts kept, labelled with their pile direction
Artificial Grass Reference Tables
The roll widths that decide the layout, published infill rates and base depths by application, seam tape and adhesive coverage, fastener spacings, and the conversions behind every figure on this page — with the caveats named rather than hidden.
How a Lawn Fits a Roll Width
The same lawn width against the two most common roll widths, showing why the roll width is the most important number in a turf order. Assumes strips run the full length, which is the direction being divided here.
| Lawn width | 15 ft roll: strips | 15 ft roll: waste | 12 ft roll: strips | 12 ft roll: waste |
|---|---|---|---|---|
| 10 ft | 1 strip | 33% (5 ft unused) | 1 strip | 17% (2 ft unused) |
| 12 ft | 1 strip | 20% (3 ft unused) | 1 strip | nil — exact fit |
| 15 ft | 1 strip | nil — exact fit | 2 strips | 60% (9 ft unused) |
| 16 ft | 2 strips | 88% (14 ft unused) | 2 strips | 50% (8 ft unused) |
| 20 ft | 2 strips | 50% (10 ft unused) | 2 strips | 20% (4 ft unused) |
| 24 ft | 2 strips | 25% (6 ft unused) | 2 strips | nil — exact fit |
| 30 ft | 2 strips | nil — exact fit | 3 strips | 20% (6 ft unused) |
| 32 ft | 3 strips | 41% (13 ft unused) | 3 strips | 13% (4 ft unused) |
Two things to take from this. First, waste is not a smooth curve — it collapses to nil at exact multiples and jumps to its worst just past one, which is why a small change to a lawn's width can save an enormous amount of turf. Second, a narrower roll is often the cheaper choice for a specific lawn even though it needs more strips, because its widths land closer to your dimension.
Infill Rates by Application
Ranges compiled from independent synthetic-turf supplier and installer guidance. These are starting points for planning, not specifications — the figure that governs your job is the one on the turf manufacturer's data sheet for your specific product and pile height.
| Application | Typical pile height | Infill type | Typical rate | Notes |
|---|---|---|---|---|
| Decorative lawn | 1.25-1.75 in (30-45 mm) | Kiln-dried silica sand | 1-2 lb/sq ft | Sources commonly cite 1.25-1.75 lb/sq ft for a 1.5-1.75 in pile |
| Lawn, 1-2 in pile | 1-2 in (25-50 mm) | Kiln-dried silica sand | 2-3 lb/sq ft | Heavier end for a longer or lower-density pile |
| Pet area / dog run | 0.75-1.25 in (20-32 mm) | Coated silica or zeolite | 2.5-3.5 lb/sq ft | Odour control is the reason for the coating, and for the heavier rate |
| Playground | 1.5-2 in (38-50 mm) | Silica, TPE or blend | 2-3 lb/sq ft | Fall protection comes from the shock pad, not from the infill |
| Putting green | 0.4-0.75 in (10-19 mm) | Fine rounded silica | 1.5-2.5 lb/sq ft | Applied in stages with rolling between; it sets the green's speed |
| Heavy / sports use | 1.5-2.5 in (38-64 mm) | Sand and rubber blend, about 70:30 | 4-5 lb/sq ft | Heavier products, cited up to 5 lb/sq ft at 50-80 oz face weight |
| Over a hard surface | 1-1.5 in (25-38 mm) | Kiln-dried silica sand | ~1 lb/sq ft | Lighter: the adhesive is holding the turf, not the infill weight |
One thing worth reconciling, because the two halves of the published guidance appear to contradict each other. Infill is often described as filling the pile "to just below the fibres", but the rates above cannot produce that and are not meant to. Silica sand is roughly 100 lb per cubic foot, so a residential 1.5 lb/sq ft is about 0.18 in of sand — 12% of a 1.5 in pile, not most of it. Across every application in this table the infill ends up somewhere between roughly 10% and 40% of the pile height. That is correct: the infill is ballast at the base of the blades, and filling higher flattens the lawn rather than supporting it. The calculator reports the depth your rate actually produces so you can see where it lands.
Base Depth & Materials
| Application | Compacted base depth | Suitable material | Notes |
|---|---|---|---|
| Decorative lawn | 3-4 in (75-100 mm) | Class II road base, MOT Type 1, 3/4 in minus crushed stone | The standard residential figure across published guidance |
| Pet area, heavy traffic, heavy rain | 4-5 in (100-125 mm) | As above, with attention to drainage | Depth here is about drainage as much as load |
| Playground | 4 in (100 mm) plus shock pad | As above, screeded flat | Pad thickness set by the equipment's critical fall height |
| Putting green | 4 in (100 mm) plus fine screed | Crushed base under decomposed granite | Flatness matters more here than anywhere else |
| Light vehicle or heavy load | 6 in or more (150 mm+) | Engineered — seek specific advice | Beyond what a general calculator should specify |
| Over concrete or decking | None | The existing slab IS the base | Bonded installation; check it already drains |
Never use rounded pea gravel as a turf base — round stone rolls under load instead of locking together, and the surface ripples within a season regardless of how well it was compacted. Compact in lifts of 1-2 in: a plate compactor only densifies the top couple of inches.
Seam Tape & Adhesive Coverage
| Pack | Seam coverage (12 in tape) | Full glue-down coverage | Best for |
|---|---|---|---|
| 5 gallon bucket | ~250 linear ft | ~360 sq ft | Long seams and any glue-down; cheapest per foot |
| 1 gallon pail | ~50 linear ft | ~72 sq ft | A single seam or a small repair |
| 29 oz cartridge (gun) | ~13 linear ft | ~19 sq ft | Short seams, perimeter beads, touch-ups |
| Seam tape, 12 in x 328 ft (100 m) | 328 ft of joint | Not applicable | The standard roll for a whole job |
| Seam tape, 12 in x 150 ft | 150 ft of joint | Not applicable | A smaller job with two or three seams |
| Self-adhesive tape, 6 in x 75 ft | 75 ft of joint | Not applicable | Quick small-job seams, less ultimate strength |
Seam coverage is per LINEAR foot of tape; glue-down coverage is per SQUARE foot of surface. They are different applications, not two ways of quoting the same number — using one for the other is out by an order of magnitude. Figures are typical published coverages; always check the product label.
Fastener Spacing
| Where | Spacing | Fasteners per 100 ft or 100 sq ft | Notes |
|---|---|---|---|
| Perimeter, exposed edge | 3 in (75 mm) | ~401 per 100 ft | Gates, paths, anywhere a foot or a mower can catch it |
| Perimeter, standard | 4-6 in (100-150 mm) | ~201-301 per 100 ft | The published range for a turf perimeter |
| Seams, nailed (no tape) | 3-6 in (75-150 mm) | ~201-401 per 100 ft | Only where seams are fastened rather than taped |
| Field grid, 12 in | 12 in (300 mm) | 100 per 100 sq ft | Heaviest use; rarely needed on a decorative lawn |
| Field grid, 18 in | 18 in (450 mm) | ~45 per 100 sq ft | Pet runs, play areas, sports surfaces |
| Field grid, 24 in | 24 in (600 mm) | 25 per 100 sq ft | Commonly cited as 2 ft on centre through the field |
| Field, none | Perimeter and seams only | 0 | Normal for a residential lawn — infill weight holds the field |
Perimeter counts are fence-post style: one fastener at each end of a run as well as those between, so a 100 ft run at 4 in centres is 301 rather than 300. Use 5-6 in galvanised turf nails (40D-60D) or U-pins into a compacted base; nothing can be driven into concrete, where the turf is bonded instead.
Conversions & Densities Used
| Quantity | Conversion or typical value | Where it applies |
|---|---|---|
| 1 sq m | 10.7639 sq ft | Every area figure on this page |
| 1 cu yd | 27 cu ft = 0.7646 m³ | Base aggregate volumes |
| 1 US ton | 2,000 lb = 907.2 kg | Aggregate and infill weight |
| 1 tonne | 2,204.6 lb = 1,000 kg | Aggregate and infill weight |
| 1 lb/sq ft | 4.882 kg/m² | Infill rate, either way round |
| Class II road base / MOT Type 1 | ~103 lb/cu ft loose, ~1.39 US tons/cu yd | Base tonnage |
| Crushed stone, decomposed granite, sharp sand | ~100 lb/cu ft loose, ~1.35 US tons/cu yd | Base and levelling tonnage |
| Recycled crushed concrete | ~96 lb/cu ft loose, ~1.3 US tons/cu yd | Base tonnage |
| Silica sand infill | ~100 lb/cu ft | Infill volume (weight is what you buy) |
| Crumb rubber infill | ~33 lb/cu ft | Infill volume |
| Zeolite infill | ~50 lb/cu ft | Infill volume |
| Organic infill (cork, coconut) | ~20 lb/cu ft | Infill volume |
| Excavated soil bulking | 20-30% volume increase once dug | Sizing a skip or spoil heap |
Aggregate and infill densities are LOOSE, as-delivered figures — the basis a supplier's own tons-per-yard quote uses, and therefore the right density to apply to a loose ordered volume. They genuinely vary with grading and moisture, so treat any tonnage here as a planning estimate and confirm it with the supplier you are buying from.
How to Use This Calculator
- Confirm the roll width first. Everything else depends on it. Ask your supplier for the width of the specific product code you are ordering, not their general range — a lawn planned against 15 ft and delivered on 12 ft needs a different number of strips and a different number of seams.
- Pick the application. Lawn, pet area, playground, putting green, hard surface or sports use each seed a sensible pile height, infill type, infill rate and base depth. Choosing a hard surface also switches the whole installation to a bonded one, since there is nothing to nail into.
- Enter each area as a rectangle. Break an L-shape or a curved lawn into the two or three rectangles it is made of, measuring each to its widest point. That is how the turf gets cut anyway, and a single lumped area cannot be strip-planned at all.
- Read the strip direction the calculator chose, and the saving. On automatic it picks the cheaper direction per area and tells you what the other would have cost. If the pile has to lean a particular way for appearance, fix the direction and take the number as the price of that decision.
- Check the near-miss advisory before the layout is built. If your lawn sits just past a whole roll width, the calculator says so and says what narrowing it would save. This is the single most valuable thing on the page while a design can still change.
- Decide on offcut planning. Leave it off for a simpler job on site where each area comes off its own strips. Turn it on to cut narrow end pieces side by side from shared lengths and get the cut list — less turf, more care needed.
- Work down the groundwork and materials. Base material and depth, the levelling course, the weed barrier and its overlap, the infill type and rate, the seam method, the fixing method and spacing, and the edging. Each one you turn off simply drops out of the bill of materials.
- Price the lines you are buying. Every price is optional and only the ones you fill in are totalled. Turf can be priced per square foot, per square metre, or per linear foot or metre off the roll, whichever way your supplier quotes.
- Use Compare to test a decision. Two roll widths, two strip directions, sand against a coated infill, a nailed installation against a bonded one — set up both sides and export the comparison as a PDF.
- Take the checklist to site. Download it with your own figures filled in, and work through the essential checks before ordering and the full QC list as the job proceeds.
Practical Tips
- Design the lawn to the roll, not the roll to the lawn. If the layout is not yet built, a lawn whose width is a whole multiple of the roll width has zero roll-width waste. Taking a foot out with a paved border, a planting bed or a run of stepping stones can delete an entire strip — the length of the lawn in turf, for a foot of coverage.
- Have the pile lean toward where you look from. Turf viewed into the lean looks richer and more even; viewed with the lean it can look flat and shiny. Stand where you will actually see the lawn from — usually the back door or the patio — and run the pile toward you.
- Let the turf relax in the sun before you cut anything. It comes off the roll with creases and memory in the backing, and it moves with temperature. Roll it out in position for a few hours in the warm so you are cutting and seaming it at the size it will stay at. Seams cut cold on a cold morning can open on the first hot afternoon.
- Trim the factory selvedge from the back, between stitch rows. The manufactured edge carries backing with no tufts, and left on it shows as a bald line down the seam. Cut from the back with a fresh blade between two rows of stitching, so the joint closes with a full row of tufts each side and disappears into the pile.
- Put the seams where nobody walks or looks. Even a good seam is the weakest line in the lawn and the first place wear shows. Where two directions cost the same turf, choose the one that puts the joint along an edge, under a low-traffic route, or behind a planting bed — not down the middle of the path from the back door.
- Spend your time on the screed, not the turf. The turf is the easy part. Every stone, dip and soft spot in the base telegraphs through a short pile, and no amount of brushing fixes it afterwards. A fine screeded and rolled levelling course is what separates a lawn that looks installed from one that looks laid down.
- Infill in two or three passes, with a power broom between. Dumped all at once it bridges on top of the pile and leaves the blades flattened underneath. Spread a portion with a drop spreader, broom it down to the backing against the pile direction, then repeat. A power broom does a job a stiff brush genuinely cannot.
- Test the drainage with buckets before you sign the job off. Pour several over the lowest point and watch. It should be gone in a minute or two with no dip and no standing water. Finding a drainage problem with a bucket costs nothing; finding it in the first heavy rain costs the lawn.
- Order one batch, and check it before cutting. Colour and pile vary slightly between production batches, and the difference shows most at a seam. Ask for a single batch for the whole job; where a change is unavoidable, put the boundary at a physical break rather than a seam in open ground, and compare the two in daylight first.
- Keep the big offcuts, and mark the pile direction on the back. A spare piece of the same batch is the only invisible repair you will ever get for a burn, a dig-up or a bad cut. An arrow on the backing costs a second; a patch let in the wrong way round is as visible as the damage it replaced.
- Think about surface temperature before you commit.Synthetic turf in full sun runs considerably hotter than grass or paving — hot enough to matter barefoot, and for dogs' paws. Crumb rubber is the hottest infill, light sand and organic infills the coolest. Shade, a light infill and a hose-down before use all help; a south-facing roof terrace with no shade is the worst case there is.
Common Mistakes
- Ordering the lawn area plus 10%. The single most expensive mistake in this subject. Turf comes in fixed-width rolls, so the roll-width waste is set by geometry and can be anything from nil to over 80% — nothing like a flat 10%. A 20 ft by 16 ft lawn needs 480 or 600 sq ft of roll depending which way the strips run, against 320 sq ft of lawn. Both are a long way past 352.
- Laying one strip at ninety degrees to another to use up an offcut. The blades lean one way down the roll, so a rotated piece reads as a visibly different shade of green from most angles, and brushing will not fix it because the lean is manufactured in. This is why offcuts can only be reused in the same orientation, and why a partial strip still costs a full roll width.
- Multiplying the compacted base volume by the compaction percentage. If compacting takes 20% out, the loose volume needed is the compacted volume divided by 0.80 — 25% more, not 20%. Multiplying leaves the order roughly 4% short, which reliably shows up at the final lift with the supplier already gone.
- Digging only to the base depth.The excavation has to take the base, any levelling course, and the turf's own pile plus backing. Miss the last two and the finished lawn stands proud of its edging, path or threshold — the most obvious visual tell of a DIY installation, and almost impossible to fix afterwards without lifting everything.
- Using pea gravel or rounded stone for the base. Round stone rolls under load instead of interlocking, so the surface ripples and rutts within a season no matter how thoroughly it was compacted. It has to be angular crushed material with fines in it.
- Dumping the full base depth and compacting the top. A plate compactor only densifies the top inch or two. A 4 in base laid in one go is hard on top and loose underneath, and it settles unevenly under traffic. Spread and compact in lifts of 1-2 in.
- Treating the perforated backing as a drainage solution. Water passes through the turf easily; the question is where it goes next. A flat base over clay becomes a shallow reservoir under the lawn, which smells in a pet area and freezes in winter. Build in a fall and give the water somewhere to leave.
- Butting weed membrane strips instead of overlapping them.The butt joint is exactly where weeds come through. Strips need lapping by around 6 in, which reduces each strip's effective coverage — so a quantity worked out by dividing the lawn area by the roll area is short before you start.
- Quoting seam adhesive by area, or glue-down adhesive by the linear foot. A seam bead onto 12 in tape covers roughly 250 linear ft per 5 gallon bucket; a full glue-down covers roughly 360 sq ft per bucket. They are different applications, and swapping the figures is out by an order of magnitude in whichever direction you go.
- Spacing perimeter fasteners like field fasteners. The edge is where turf lifts, and published guidance puts perimeter fasteners at 3-6 in, not the 12-24 in used across the field. A perimeter at wide centres is the commonest cause of an edge lifting in the first year.
- Applying all the infill in one pass. It bridges on top of the pile, leaving the blades flattened underneath and the surface uneven, and no amount of brushing afterwards fully recovers it. Two or three passes with a power broom between is the difference.
- Using plain silica sand in a pet area. Plain sand holds the ammonia from urine and releases it in warm weather. A coated or antimicrobial grade, or zeolite, is what controls the odour — and neither works over a base with nowhere for liquid to go.
- Assuming the turf provides playground fall protection.It provides almost none. Fall attenuation comes from the shock pad beneath, matched to the critical fall height of the specific equipment and verified against the pad manufacturer's tested data. Nothing on this page substitutes for that verification.
- Nailing the perimeter before the turf is stretched flat. Wrinkles trapped under a fixed edge cannot be pulled out afterwards. Work from one fixed edge toward the opposite one, stretching as you go.
- Budgeting the turf on the lawn area. You pay for the roll, not the lawn. On a lawn that sits awkwardly against the roll width, pricing on lawn area understates the turf line by 30-50% — which is usually the largest single item in the job.
Limitations
- Every area is treated as a rectangle. A curved, tapered or irregular lawn has to be broken into the rectangles it is made of, each measured to its widest point — which is how the turf is actually cut, but it means the calculator cannot tell you how much of a curve you will trim away. That is what the cutting allowance is for.
- The layout plans full-width strips running one way. It does not model cross-seams part-way down a strip, piecing a long run from two shorter lengths, or inlaid features like a contrasting border, a putting cup surround or a painted line — all of which change both the cut list and the seam length.
- Offcut planning uses a simple, explicable side-by-side packing of narrow end pieces, deliberately rather than an optimal two-dimensional packer. A plan nobody can follow on the ground saves nothing, so it will sometimes leave material on the table that a perfect nesting would have used.
- It does not design a drainage scheme. It sizes an aggregate base at the depth you specify; whether that base drains depends on your subgrade, your falls, your outfall and your rainfall, and a lawn in a hollow or over clay may need a French drain, a channel or a soakaway that nothing here accounts for.
- It does not certify a playground fall height. It sizes the shock pad you specify. Fall attenuation must be verified against the critical fall height of the specific equipment and the pad manufacturer's tested data under the applicable playground safety standard.
- Aggregate and infill densities are typical loose figures, not measured ones. Real density varies with grading, moisture and source, so a tonnage here is a planning estimate to confirm with your own supplier — never a delivery ticket.
- Compaction is taken as a single volume-loss percentage across the whole base. It does not model compaction to a specified Proctor density, lift-by-lift behaviour, subgrade settlement, or aggregate lost into soft ground — which is a real quantity on poor subgrade and the reason a separation geotextile exists.
- Pack sizes and coverages are typical published figures for planning. Bag weights, roll lengths, tape lengths, adhesive coverage and fastener pack counts all vary by manufacturer, and adhesive coverage in particular varies with temperature, substrate and trowel notch.
- Cost is a materials estimate from the lines you price. It excludes labour, plant and tool hire, delivery, skip hire and spoil disposal, site access difficulties, existing surface removal, edging stakes and fixings, and any drainage work — several of which together commonly exceed the materials on a real installation.
- It says nothing about product quality. Face weight, pile density, backing construction, UV stabilisation and warranty terms vary enormously between products at the same pile height, and two lawns with identical quantities from this calculator can last very different lengths of time.
- This calculator estimates material quantity for planning and procurement. It does not replace a site survey, a drainage design, a structural assessment of a roof terrace or balcony, or the turf manufacturer's own installation instructions — which take precedence over anything here, particularly where a warranty depends on them.
Disclaimer: This calculator provides approximate results for planning and estimation purposes only. Actual requirements may vary based on site conditions, materials, workmanship, and local building regulations. Always consult a qualified engineer, architect, or construction professional before making final decisions.