Fill & Backfill Calculator — m to m³, tonnes, trucks, cost
How to use this calculator
Calculate volume, weight, and truck loads for fill and backfill in metric. Three shapes: rectangle, trench, or around a foundation. Select material type with preset density and apply a compaction/shrinkage factor (15–25%) to determine loose volume to order.
Materials — Clean fill (1.4 t/m³), structural fill (1.6 t/m³), gravel (1.65 t/m³), sand (1.55 t/m³), clay (1.5 t/m³), topsoil (1.25 t/m³).
Compaction — Loose fill compacts by 15–25%. Order extra to reach required compacted volume per EN 13242.
Saved Calculations
| Time | Shape | Material | Compact m³ | Loose m³ | Tonnes | Trucks | Cost |
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How to Calculate Fill and Backfill (Metric)
This calculator estimates volume, weight, and truck loads for fill and backfill operations in metric units. Supports rectangular areas, trenches, and foundation backfill. Material densities per EN 13242 include clean fill, structural fill, gravel, sand, clay, and topsoil.
Formulas
Compacted volume = L × W × depth. Loose volume = compacted × (1 + shrinkage%). Weight = loose volume × density (t/m³). Truck loads = ceil(loose volume / 10 m³). Foundation backfill = (outer L × W − foundation L × W) × depth.
FAQ
Why order extra? Loose fill compacts 15–25% during placement and compaction. Order loose volume, not compacted volume.
How many m³ per truck? Standard dump truck ~10 m³, large tipper ~14–16 m³. Weight limits may reduce volume for heavy materials like gravel.
