TryBuildCalcGravel Driveway Calculator (Sub-base, Base Course & Surface)
Find your driveway's sub-base, base, and surface gravel instantly.
🕒 Last updated: September 7, 2026
Inputs
ℹ️L-Shaped models a main run plus a second connected section — an apron, turn, or widened area — as two rectangles added together.
ℹ️Distance from the street/curb to the garage or parking area.
ℹ️Single-car driveways are typically 10-12 ft wide; double-car driveways are typically 20-24 ft.
Sub-base (Bottom Layer)
ℹ️6 in is standard for residential driveways; go to 8 in for soft/clay soil or heavy vehicles.
Base Course (Middle Layer)
ℹ️A compacted crusher-run middle course is the ideal 3-course driveway system — some lighter-duty driveways skip it and go straight from sub-base to surface.
Surface Course (Top Layer)
ℹ️The visible, walked/driven-on layer — 2 in is a common standard depth.
ℹ️Crushed/angular materials interlock and hold up under vehicle loads better than rounded river/pea gravel.
Delivery
ℹ️Bulk truck delivery is standard for the sub-base and base course, always. Bagged is only offered for the surface layer, for a small area or patch.
ℹ️Standard dump trucks carry around 10-12 tons per load. Applies to every bulk-delivered layer.
Geotextile Fabric & Edging
Standard practice between subgrade and sub-base — prevents soil migration into the base and reduces long-term rutting.
Cost
Total Gravel Needed
14.021 tons
200 sq ft, 12" total depth
Area
200 sq ft
20 × 10 ft
Sub-base
Quarry Process (QP) — US driveway base, 6" deep
Volume: 3.7 cu yd
Weight: 7.172 tons
1 partial delivery: 7.17t (truck capacity 10t)
Base Course
Quarry Process (QP) — US driveway base, 4" deep
Volume: 2.47 cu yd
Weight: 4.781 tons
1 partial delivery: 4.78t (truck capacity 10t)
Surface Course
Crushed Granite (10mm), 2" deep
Volume: 1.23 cu yd
Weight: 2.068 tons
1 partial delivery: 2.07t (truck capacity 10t)
Geotextile Fabric
Area (+10% overlap): 220 sq ft
Rolls needed (12.5 × 360 ft each): 1
Assumptions Used
Standard US residential gravel driveway, rectangular or L-shaped, built in up to 3 courses — sub-base, an optional base course, and a visible surface course — following the widely-cited layered driveway construction system rather than a single uniform depth. Each layer's weight uses the selected material's published density with a 15% compaction allowance and 8% waste, matching the site's general gravel-weight calculator. Truck loads are computed per layer using the entered truck capacity; the surface layer can instead be bagged for a small area. Geotextile fabric area includes a 10% overlap allowance for seams; standard roll size is 12.5 × 360 ft. Edging length sums each section's own full perimeter — for L-shaped mode this is a conservative over-estimate (it doesn't subtract the shared internal edge where the two sections join). This calculator computes material quantities only — it does not verify subgrade compaction adequacy, local drainage requirements, or structural design for unusual soil or loading conditions.
Bill of Materials
Main material: 7.172 tons + recommended tools
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Bill of Materials
Main material: 7.172 tons + recommended tools
Computed items reflect your entered dimensions and layer choices; consumables below are general recommendations — actual needs vary by product and site conditions.
For Your Job
Sub-base
Base Course
Surface Course
Geotextile Fabric
General Tools & Consumables
Landscape stakes / fabric pins
Edging stakes or spikes
Plate compactor or roller
Landscape rake
Wheelbarrow or skid steer
String line / grade stakes
Tape measure
Weed barrier fabric (if not using structural geotextile)
Safety glasses & work gloves
Diagram simplified for clarity (not to scale) — layer thicknesses shown proportionally, footprint shown schematically.
What Is a Gravel Driveway Calculator?
A gravel driveway calculator finds the sub-base, base course, surface gravel, geotextile fabric, and edging needed for a gravel driveway — rectangular, or L-shaped with a main run plus a connected apron or turn — built in up to 3 layers, not a single uniform depth. Most online gravel calculators only compute one depth for one material; this one models the actual layered construction system contractors use.
This calculator computes material quantities only. It does not verify subgrade compaction adequacy, local drainage requirements, property line/setback compliance, or structural design for unusual soil or loading conditions.
Why 3 layers instead of 1:
- Sub-base and base course need a compactable, fines-plus-stone material (crusher run/quarry process) that locks together — a decorative, single-size gravel won't compact into a stable structural layer
- The surface course is a different, often decorative material — what you actually see and drive on
- Each layer's weight and truck-load count are computed independently, since sub-base, base, and surface are commonly different materials from different suppliers
- Geotextile fabric between subgrade and sub-base is standard, widely-recommended practice (though not strictly mandatory) — it prevents the base stone from migrating into the soil below over time
Gravel Driveway Calculator Formula: How Is It Determined?
Each layer's volume, weight, and truck loads calculated separately using its own depth and material, then combined into one material takeoff.
Step 1 — Layer Volume & Weight
Volume = Area x Layer Depth
Weight = Volume x (1 + 15% compaction) x Material Density x (1 + 8% waste)
Applied separately to the sub-base, the optional base course, and the surface course — each with its own depth and material density. The 15% compaction and 8% waste allowances match the site's general gravel-weight calculator.
Step 2 — Truck Loads
Full Loads = floor(Layer Weight / Truck Capacity)
Total Loads = Full Loads + 1 if a partial load remains
Computed per layer using the entered truck capacity — a bulk-delivered sub-base, base course, and surface course each get their own load count, since they're commonly delivered separately.
Step 3 — Geotextile Fabric
Order Area = Driveway Area x (1 + 10% overlap)
Rolls = ceil(Order Area / Roll Area)
A 10% overlap allowance covers the overlap needed at every fabric seam. Standard roll size assumed is 12.5 x 360 ft (4,500 sq ft).
Step 4 — Edging
Perimeter = Sum of each section's own 2 x (Length + Width)
For L-shaped mode, this sums BOTH sections' full perimeters — a conservative over-estimate, since it doesn't subtract the shared internal edge where the two sections join. Over-ordering edging material is the safe direction.
Worked Example
This example walks through your current inputs above, using the same steps as the Formula section.
Input Values Used
| Input | Value | Why it is used |
|---|---|---|
| Shape | 20 ft / 10 ft | Sets area for every layer |
| Layers | 12" total (6" sub-base + 4" base + 2" surface) | Sets volume and weight per layer |
| Fabric / Edging | Included / Not included | Sets fabric roll and edging length |
Step 1 — Sub-base
| Calculation | Result |
|---|---|
| Volume = 200 sq ft x (6/12) ft | 100 cu ft (3.7 cu yd) |
| Weight = Volume x (1 + 15%) x density x (1 + 8%) | 7.172 tons |
| Truck loads = ceil(7.172 / 10) | 1 loads |
Step 1b — Base Course
| Calculation | Result |
|---|---|
| Volume = 200 sq ft x (4/12) ft | 66.67 cu ft (2.47 cu yd) |
| Weight = Volume x (1 + 15%) x density x (1 + 8%) | 4.781 tons |
Step 1c — Surface Course
| Calculation | Result |
|---|---|
| Volume = 200 sq ft x (2/12) ft | 33.33 cu ft (1.23 cu yd) |
| Weight = Volume x (1 + 15%) x density x (1 + 8%) | 2.068 tons |
Step 3 & 4 — Fabric & Edging
| Calculation | Result |
|---|---|
| Fabric order area = 200 x (1 + 10%) | 220 sq ft (1 rolls) |
Therefore, this 20 ft x 10 ft gravel driveway needs approximately 14.021 tons of bulk gravel across its layers, 1 roll(s) of geotextile fabric.
Essential Checklist+−
Complete these critical checks before approving the work or proceeding to the next construction stage.
✓Layout & Site Inputs+-
- Driveway dimensions (length/width, or each section's length/width for an L-shaped layout) confirmed from an actual field measurement or site plan, not assumed
- Property line, easement, and any local setback requirement confirmed before finalizing the driveway footprint
- Utility locate service called (811 or local equivalent) before any excavation for the driveway or its base
- Positive drainage slope and crown (center-high cross-section) planned before finalizing grade
✓Subgrade Preparation & Geotextile Fabric+-
- Subgrade compacted and confirmed stable before placing any gravel, not left loose or organic-laden
✓Layer Construction & Compaction+-
- Sub-base compacted in lifts (not dumped and left loose), typically to at least 95% of maximum dry density
Full QC Checklist+−
Verification checklist for gravel driveway material takeoffs — covering layout inputs, subgrade/geotextile preparation, layer compaction, and edging/drainage/maintenance. Use the Essential Checklist for critical checks before finalizing, expand to Full QC Checklist for complete verification.
✓Layout & Site Inputs+-
- Driveway dimensions (length/width, or each section's length/width for an L-shaped layout) confirmed from an actual field measurement or site plan, not assumed
- Property line, easement, and any local setback requirement confirmed before finalizing the driveway footprint
- Utility locate service called (811 or local equivalent) before any excavation for the driveway or its base
- Positive drainage slope and crown (center-high cross-section) planned before finalizing grade
- Sub-base and base course materials selected genuinely compact into a stable structural layer, not just a decorative-looking gravel
✓Subgrade Preparation & Geotextile Fabric+-
- Subgrade compacted and confirmed stable before placing any gravel, not left loose or organic-laden
- Geotextile fabric (if included) installed directly on the compacted subgrade, with seams overlapped per the manufacturer's spacing, not butted edge-to-edge
- Local frost depth considered for sub-base thickness in cold climates
✓Layer Construction & Compaction+-
- Sub-base compacted in lifts (not dumped and left loose), typically to at least 95% of maximum dry density
- Base course (if included) compacted separately from the sub-base, not treated as one combined uncompacted layer
- Actual placed depth of each layer spot-checked at multiple points across the driveway, not assumed uniform from the delivered tonnage alone
- Surface material confirmed appropriate for the local climate — decomposed-granite-style materials in particular can wash out in wet climates
✓Edging, Drainage & Maintenance+-
- Edging/border (if included) installed before the final surface layer is spread, not added afterward
- Drainage crown and grade confirmed maintained after construction, not disturbed by later grading or landscaping work
- Periodic maintenance (regrading, top-up gravel, weed control) planned for, not treated as a one-time installation
Gravel Driveway Reference Tables
Typical layer depths by course, and the 10% overlap allowance used for fabric.
| Layer | Typical Depth | Material Type |
|---|---|---|
| Sub-base | 4-8 in | Compactable crusher-run / quarry-process (fines + stone) |
| Base course (optional) | 3-4 in | Same compactable family as sub-base |
| Surface course | 1-3 in | Decorative or drainage gravel — pea gravel, crushed granite, decomposed granite |
Edging Material Comparison
| Material | Typical Service Life | Notes |
|---|---|---|
| Landscape Timber | 10-15 years | Cheapest, easiest DIY install |
| Steel / Aluminum | 15-50+ years | Holds curves well, longest-lasting |
| Plastic | Shortest | Cheapest material cost, but commonly cracks/buckles under vehicle contact |
| Paver / Stone Border | Long | Durable and DIY-friendly, higher material cost |
When should you use this gravel driveway calculator?
- Planning sub-base, base course, and surface gravel quantities before ordering material for a full driveway build.
- Deciding between a full 3-course system and a simpler 2-course (sub-base + surface) build for a lighter-duty driveway.
- Sizing geotextile fabric rolls and edging material alongside the gravel itself.
- Scheduling delivery by knowing how many truck loads each layer needs.
- Cross-checking a contractor's gravel driveway material quote against an independent estimate.
Quick Gravel Driveway Tips
- Call 811 (or your local utility locate service) before any excavation for the driveway or its base.
- Plan a slight crown (higher in the center) plus overall grade before spreading any material — water pools and ruts a flat gravel surface over time.
- Compact each layer separately, in lifts, before moving to the next — don't treat the whole depth as one uncompacted pile.
- Install edging before the final surface layer, not after, for a cleaner contained edge.
- Budget for periodic top-up material — surface gravel migrates and thins with traffic and weather over time.
- Choose a compactable, fines-plus-stone material for the sub-base and base course — plain decorative gravel won't lock together into a stable structural layer.
Common Mistakes
- Using a single-size decorative gravel for the structural sub-base or base course, which won't compact into a stable layer.
- Skipping geotextile fabric, letting the base stone gradually migrate into the subgrade soil below.
- Not compacting each layer separately, leaving a weak, unstable base under the visible surface.
- Building a flat driveway with no crown or drainage grade, leading to pooling and rutting.
- Installing edging after the surface layer instead of before, making a clean contained edge much harder.
- Choosing a decomposed-granite-style surface material in a wet climate, where it commonly washes out.
- Treating a gravel driveway as maintenance-free — surface material needs periodic regrading and top-up.
Limitations
- Standard US residential gravel driveway, rectangular or L-shaped (two rectangular sections) — a driveway with curves or a third connected section needs separate calculation for that additional section.
- For L-shaped mode, edging length sums both sections' full perimeters, a conservative over-estimate that doesn't subtract the shared internal edge.
- Compaction (15%) and waste (8%) allowances are fixed assumptions applied to every layer, matching the site's general gravel-weight calculator, not user-adjustable per layer.
- Does not verify subgrade compaction adequacy, local frost depth requirements, or drainage/crown compliance.
- Does not verify structural design for unusual soil conditions or non-standard vehicle loading — a geotechnical opinion may be needed for marginal sites.
- Cost estimation covers sub-base, base course, surface, fabric, and edging material only — excavation, subgrade compaction labor, and installation labor are not included.
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.