TryBuildCalcGSB Quantity Weight Calculator(Granular Sub-Base Weight & Truck Loads)
Calculate GSB weight with compaction.
🕒 Last updated: June 17, 2026
Inputs
ℹ️Auto-filled from aggregate type. Edit it if your supplier provides a tested bulk density.
Dimensions of the Area to be Filled / Covered
Enter the length and width of your site area, and the thickness/depth of the aggregate layer you need.
ℹ️Enter your actual quoted material rate. The calculator does not estimate market price.
16.20 m³
572.10 ft³ • 5.72 brass
GSB (Granular Sub-Base)
30,845 kg
30.85 tonnes
32,387 kg
32.39 tonnes • +5% wastage included
3.2 loads
4 full load(s), based on Standard (10T)
Density Used: 1,700 kg/m³
Moisture Condition: DRY
IS Standard: IS 383:2016
Aggregate Quantity Visualization
Approximate results for planning only. Verify with a professional.
GSB order quantity with compaction
GSB layers are compacted, so finished layer volume usually needs additional loose material.
This page pre-fills a 12% compaction allowance for sub-base planning.
- Default density: 1,700 kg/m3.
- Default compaction: 12%.
- Useful for road base and plinth sub-base layers.
What Is an Aggregate Weight Calculator?
When you're ordering sand, gravel, or crushed stone for a construction project, the supplier quotes by weight — in tonnes or quintals — but on site, you're working with dimensions: length, width, and depth of a slab, trench, or fill area. An aggregate weight calculator bridges this gap.
It converts your project's physical dimensions into the actual weight of aggregate you need to order — accounting for the material type, any site wastage, and whether the layer will be compacted.
This calculator is built for Indian residential construction. It covers:
- Fine aggregates: river sand, M sand, stone dust
- Coarse aggregates: 20mm and 40mm crushed granite, limestone, gravel
- Road/infrastructure aggregates: GSB, WMM
- Recycled aggregates (RCA) per IS 383:2016
Whether you're calculating aggregate for a concrete slab, a backfill trench, a sub-base layer, or a plinth filling, this tool gives you a reliable order quantity in minutes.
How Is Aggregate Weight Calculated?
Aggregate weight is calculated by first finding the required volume, then converting that volume into weight using bulk density. The calculator can also add compaction, moisture, wastage, truck load, and cost adjustments so the final result is useful for actual material ordering.
Step 1 — Calculate Finished Volume
Volume (m³) = Length × Width × Depth
If depth is in mm: Depth (m) = Depth (mm) ÷ 1000
Finished volume is the actual volume of aggregate required in the completed layer. For example, if the area is 12 m long, 9 m wide, and 150 mm thick, then depth = 150 ÷ 1000 = 0.15 m. So, volume = 12 × 9 × 0.15 = 16.20 m³.
Step 2 — Add Compaction Allowance
Compaction Allowance = Finished Volume × (Compaction % ÷ 100)
Loose Volume = Finished Volume + Compaction Allowance
Aggregates are usually delivered in loose condition. After spreading and compaction, the same material occupies less volume. If the finished volume is 16.20 m³ and compaction is 10%, then compaction allowance = 16.20 × 10% = 1.62 m³. Loose volume = 16.20 + 1.62 = 17.82 m³.
Step 3 — Convert Volume to Weight
Aggregate Weight (kg) = Loose Volume (m³) × Bulk Density (kg/m³)
Bulk density is the weight of aggregate per cubic metre, including the air voids between particles. If loose volume is 17.82 m³ and bulk density is 1,600 kg/m³, then aggregate weight = 17.82 × 1,600 = 28,512 kg, or 28.51 tonnes.
Step 4 — Apply Moisture Adjustment
Moisture Adjusted Weight = Aggregate Weight × Moisture Factor
Wet or saturated aggregate weighs more than dry aggregate. If dry weight is 28,512 kg and the selected moisture factor is 1.05, then adjusted weight = 28,512 × 1.05 = 29,938 kg. This helps users understand why wet material may show a higher weight for the same volume.
Step 5 — Add Wastage
Wastage Quantity = Adjusted Weight × (Wastage % ÷ 100)
Final Order Quantity = Adjusted Weight + Wastage Quantity
Wastage covers spillage during unloading, handling loss, spreading loss, and material left on the truck bed. If adjusted weight is 29,938 kg and wastage is 5%, wastage quantity = 29,938 × 5% = 1,497 kg. Final order quantity = 29,938 + 1,497 = 31,435 kg, or 31.44 tonnes.
Step 6 — Convert to Tonnes, Truck Loads, and Cost
Tonnes = Final Weight (kg) ÷ 1000
Truck Loads = Final Weight (kg) ÷ Truck Capacity (kg)
Estimated Cost = Final Weight (tonnes) × Cost per Tonne
Suppliers commonly quote aggregate in tonnes, brass, or truck loads. The calculator converts the final weight into tonnes, estimates the required number of truck loads, and calculates material cost using your entered supplier rate.
Quick Rule of Thumb
- 1 m³ of 20mm aggregate usually weighs around 1.55–1.65 tonnes.
- 1 brass, or 100 cft, of 20mm aggregate usually weighs around 4.4–4.7 tonnes.
- A 10-tonne truck usually carries around 6–6.5 m³ of 20mm aggregate.
Real-World Aggregate Weight Calculation Example
This example uses the active calculator inputs and explains the complete calculation method step by step. Each table shows the formula, values placed into the formula, and the final result.
Input Values Used
| Input | Value | Purpose |
|---|---|---|
| Aggregate type | GSB (Granular Sub-Base) | Used to select practical bulk density |
| Length | 12 m | Site length to be filled or covered |
| Width | 9 m | Site width to be filled or covered |
| Depth / Thickness | 150 mm | Required aggregate layer thickness |
| Bulk density | 1,700 kg/m³ | Converts aggregate volume into weight |
| Compaction factor | 12% | Extra loose material required before compaction |
| Moisture condition | DRY / factor 1 | Adjusts weight for dry, SSD, or wet aggregate |
| Wastage factor | 5% | Allows for unloading, handling, and spreading loss |
| Truck capacity | 10,000 kg | Used to estimate number of truck loads |
Step 1 — Calculate Finished Volume
Finished volume is the actual volume of aggregate required in the completed layer. When dimensions are entered, all units are first converted to metres before multiplying.
| Calculation | Formula / Substitution | Result |
|---|---|---|
| Convert length | 12 m converted to metres | 12.000 m |
| Convert width | 9 m converted to metres | 9.000 m |
| Convert depth | 150 mm converted to metres | 0.150 m |
| Finished volume | 12.000 × 9.000 × 0.150 | 16.20 m³ |
| Cubic feet | 16.20 × 35.3147 | 572.10 ft³ |
| Brass | 572.10 ÷ 100 | 5.72 brass |
Step 2 — Add Compaction Allowance
Aggregate is normally supplied loose. After spreading and compaction, it occupies less volume. The compaction allowance estimates the extra loose volume required.
| Calculation | Formula / Substitution | Result |
|---|---|---|
| Compaction allowance | 16.20 × (12 ÷ 100) | 1.94 m³ |
| Loose volume | 16.20 + 1.94 | 18.14 m³ |
Step 3 — Convert Loose Volume to Dry Weight
Bulk density converts the loose volume into weight. This calculator uses bulk density because aggregate is purchased, transported, and handled in bulk form.
| Calculation | Formula / Substitution | Result |
|---|---|---|
| Dry weight in kg | 18.14 × 1,700 | 27,540 kg |
| Dry weight in tonnes | 27,540 ÷ 1000 | 27.54 tonnes |
Step 4 — Apply Moisture Factor
Wet aggregate weighs more than dry aggregate for the same volume. The moisture factor adjusts the calculated dry weight based on the selected moisture condition.
| Calculation | Formula / Substitution | Result |
|---|---|---|
| Moisture adjusted weight | 27,540 × 1 | 30,845 kg |
| Adjusted weight in tonnes | 30,845 ÷ 1000 | 30.85 tonnes |
Step 5 — Add Wastage
Wastage covers spillage during unloading, handling loss, spreading variation, and material left on the vehicle bed.
| Calculation | Formula / Substitution | Result |
|---|---|---|
| Wastage quantity | 30,845 × (5 ÷ 100) | 1,542 kg |
| Final order quantity | 30,845 + 1,542 | 32,387 kg |
| Final order quantity in tonnes | 32,387 ÷ 1000 | 32.39 tonnes |
Step 6 — Calculate Truck Loads and Cost
| Calculation | Formula / Substitution | Result |
|---|---|---|
| Truck loads | 32,387 ÷ 10,000 | 3.24 loads |
| Rounded truck loads | Round up to next full load | 4 full load(s) |
Therefore, for this input, the required aggregate quantity is 32,387 kg, or 32.39 tonnes, including compaction, moisture adjustment, and wastage. Based on the selected truck capacity, plan for approximately 4 full truck load(s).
Practical Ordering Note
For site ordering, use the final quantity with wastage, not only the basic dry weight. If your result is close to a truck capacity limit, confirm with the supplier whether they allow partial loads or whether you need to round up to the next full truck.
Aggregate Density Reference Table
| Aggregate Type | Grade / Size | Bulk Density (kg/m³) | Material Category / Common Use |
|---|---|---|---|
| River Sand | Natural Fine | 1,550-1,650 kg/m³ | Fine Aggregate (Zone II-III) |
| M Sand | Manufactured Fine | 1,700-1,800 kg/m³ | Fine Aggregate (Zone II) |
| Stone Dust | Quarry Fines | 1,600-1,700 kg/m³ | Fine Aggregate (Zone IV) |
| Crushed Granite | 12mm | 1,580-1,650 kg/m³ | Coarse Aggregate |
| Crushed Granite | 20mm (most common) | 1,550-1,650 kg/m³ | Coarse Aggregate |
| Crushed Granite | 40mm | 1,500-1,600 kg/m³ | Coarse Aggregate |
| Crushed Limestone | 20mm | 1,450-1,550 kg/m³ | Coarse Aggregate |
| River Gravel / Pebble | 20mm | 1,400-1,500 kg/m³ | Coarse Aggregate |
| Recycled Concrete Agg. (RCA) | 20mm | 1,100-1,400 kg/m³ | Coarse Aggregate (limited use per IS 383:2016) |
| GSB (Granular Sub-Base) | IRC SP:49 Grade | 1,650-1,750 kg/m³ | Sub-base Material |
| WMM (Wet Mix Macadam) | IRC Grade | 1,750-1,900 kg/m³ | Road Base Material |
Values are loose bulk densities, not particle densities. Actual values vary by source quarry, moisture, and grading.
Wastage Factors by Use Case
| Application | Recommended Wastage | Notes |
|---|---|---|
| Concrete mix (coarse + fine agg) | 3-5% | Minimal loss in batching plants |
| Manual concrete mixing (site) | 5-8% | Higher spill during handling |
| Backfill / plinth filling | 5-10% | Depends on excavation shape |
| Road sub-base (GSB) | 5-7% | Machine-laid, lower loss |
| Plastering sand | 5-8% | Bag/loose, moderate handling loss |
| Trench filling (manual) | 8-12% | Irregular trench geometry |
Compaction Factors
| Material | Loose-to-Compacted Ratio | Add to Order |
|---|---|---|
| River Sand (backfill) | ~1.15 | 15% |
| GSB | ~1.12-1.15 | 12-15% |
| WMM | ~1.10-1.13 | 10-13% |
| Crushed Stone (sub-base) | ~1.12-1.18 | 12-18% |
| Soil-Aggregate Mix | ~1.20-1.30 | 20-30% |
Indian Unit Conversion Quick Reference
| Unit | Equivalent |
|---|---|
| 1 brass | 100 cu ft = 2.83 m³ |
| 1 MT (metric tonne) | 1,000 kg = 10 quintals |
| 1 quintal | 100 kg |
| 1 cubic metre (m³) | 35.31 cu ft |
| 1 cubic yard | 0.765 m³ |
| 1 truck load (typical India) | 5T / 10T / 14T depending on vehicle |
Aggregate Weight Verification Checklist
Use this checklist before ordering or accepting aggregate to verify site dimensions, density, compaction, wastage, moisture condition, truck capacity, and supplier unit.
✓Site Measurement Verification+-
- Length and width measured on site, not taken from architectural drawings alone.
- Depth or thickness measured from the finished surface level, not from a reference mark.
- For L-shaped or irregular areas, the area has been split into sub-rectangles and totalled.
- For sloping ground, average depth has been used across the area.
- Measurements have been cross-checked by a second person before entering into the calculator.
- Site dimensions account for any formwork, shuttering, or edge beam width that reduces aggregate area.
✓Aggregate Type and Density Verification+-
- Aggregate type selected matches the material being ordered (e.g. 20mm granite, not generic coarse aggregate).
- Bulk density value is appropriate for the source quarry and grading — not assumed from a different source.
- If supplier has provided a tested bulk density, that value has been entered instead of the default.
- For M sand, density reflects the actual manufactured source (values vary 1,650–1,850 kg/m³ by manufacturer).
- For RCA (Recycled Concrete Aggregate), structural engineer approval is obtained before use in concrete.
- Aggregate size matches the structural drawing specification (12mm / 20mm / 40mm as required).
- IS 383:2016 classification of selected aggregate is appropriate for the intended application.
✓Compaction Factor Verification+-
- Compaction factor has been applied if the aggregate will be mechanically or manually compacted after placing.
- Compaction factor is set to 0% for concrete batching aggregate (no compaction of loose aggregate before mixing).
- GSB layers use a minimum 12% compaction factor per IRC SP:49 standard practice.
- WMM layers use a minimum 10% compaction factor.
- Backfill layers use compaction factor appropriate to compaction equipment available on site.
- Compaction factor is not double-counted if volume was already measured in loose condition.
✓Wastage Factor Verification+-
- Wastage factor is at least 5% for any manually handled or poured aggregate work.
- Wastage factor reflects site conditions — open-air sites with wind exposure use higher wastage for fine aggregate.
- For trench or foundation backfill with irregular geometry, wastage is set to at least 8%.
- For machine-laid road sub-base (GSB / WMM), wastage is between 5–7%.
- Wastage factor accounts for residue left on truck beds after unloading.
- Wastage has not been set to 0% unless the application genuinely has no handling loss (e.g. batching plant direct delivery into weigh hopper).
✓Moisture Condition Verification+-
- Moisture condition reflects the actual state of aggregate being delivered — not assumed to be dry during monsoon months.
- If aggregate is sourced from a river or wet stockpile, Wet condition is selected.
- For concrete batching mix design, SSD (Saturated Surface Dry) condition is used.
- For backfill and sub-base ordering by weight, dry condition is used so order quantity is not overstated.
- Supplier has been asked whether their quoted weight is for dry or wet aggregate before placing the order.
✓Order Quantity and Supplier Unit Verification+-
- Order quantity (with wastage) is used for the purchase order, not the base dry weight.
- Supplier's quoted unit (tonne / quintal / brass / truck load) has been cross-checked against calculator output.
- 1 brass = 100 cubic feet = 2.83 m³ has been used for brass-to-tonne conversion with supplier.
- Truck capacity confirmed with the transporter — not assumed as 10 tonnes without verification.
- If truck loads result in a fraction (e.g. 3.2 loads), procurement is rounded up to 4 full loads.
- Partial truck load surcharges or minimum order quantities have been checked with supplier.
- Aggregate rate quoted is per dry tonne — clarified with supplier if quote is per wet tonne.
✓Application-Specific Checks+-
- For concrete slab aggregate: coarse and fine aggregate quantities are calculated separately using the Concrete Mix Calculator.
- For GSB sub-base: layer thickness matches the structural or road drawing, not a site assumption.
- For plinth filling: finished floor level (FFL) and natural ground level (NGL) difference has been verified from drawings.
- For trench backfill: depth used is the clear trench depth after pipe / duct placement, not the full excavation depth.
- For filter media or drainage aggregate: void content and permeability requirements checked with design engineer.
- For WMM road base: aggregate grading matches IRC Grade I or Grade II as specified in the road design report.
✓Before Placing the Order+-
- Final calculated quantity (with wastage) has been reviewed and approved by the site engineer or owner.
- Aggregate supplier's source quarry and IS 383:2016 test certificate have been requested.
- Delivery schedule confirmed — aggregate should not be stockpiled on site for more than 2–3 weeks to avoid segregation and contamination.
- Storage area on site is prepared — clear, level, and away from soil contamination or surface water.
- Number of truck loads and delivery sequence planned to avoid site congestion.
- Payment terms and unit rate confirmed in writing before first delivery.
- Calculator screenshot or export saved for project records.
Tips for Accurate Aggregate Estimation
Tip 1 — Always measure actual dimensions on site, not drawings
Drawing dimensions often do not account for formwork thickness, irregular excavation edges, or as-built variation. Measure the actual cavity or surface area before calculating.
Tip 2 — Confirm the aggregate moisture state before weighing
Wet aggregate can weigh 15-25% more than dry aggregate for the same volume. This matters when a supplier quotes by weight because wet material gives you less dry aggregate volume per tonne.
Tip 3 — For concrete, calculate coarse and fine aggregate separately
For M20 concrete using a 1:1.5:3 mix, coarse and fine aggregate quantities differ. Use the Concrete Mix Calculator for aggregate inside concrete mix proportions.
Tip 4 — Always add at least 5% wastage for hand-poured work
Even careful site work loses aggregate to spillage, wind for fine dust, spreading, and vehicle residue. For machine-laid road layers, lower wastage may be acceptable.
Tip 5 — Reconcile with your supplier's unit
Local suppliers may quote in brass, cubic feet, metric tonnes, quintals, or truck loads. Use the secondary outputs to cross-check supplier quotations before payment.
Tip 6 — GSB / WMM compaction matters more than it looks
A 150 mm compacted GSB layer may require ordering approximately 168-173 mm equivalent loose material. Skipping this factor is a common reason truck loads run short.
Calculator Limitations & Assumptions
Bulk density, not particle density: This calculator uses bulk density, which includes air voids between particles. It is appropriate for ordering but not the same as specific gravity used in concrete mix design.
Assumes dry condition by default: Default densities assume dry aggregate. Wet aggregate can weigh 10-25% more for the same volume, so use the moisture condition option when needed.
Density varies by quarry source: Granite, limestone, gravel, and recycled aggregate vary by source, grading, shape, and moisture. Ask your supplier for actual bulk density if accuracy is critical.
Shape of area assumed rectangular: For irregular L-shaped or curved areas, calculate separate sub-areas and add them together before entering the total.
No structural design output: This calculator estimates quantity only. It does not tell you what aggregate type or size is suitable for structural use.
RCA limitations per IS 383:2016: Recycled Concrete Aggregate has restricted usage: commonly limited to partial replacement, such as 25% for plain concrete and 20% for reinforced concrete up to M25 grade. This calculator does not enforce those limits. Consult your structural engineer before using RCA in concrete work.