Fill & Backfill Calculator — m to m³, tonnes, trucks, cost
How to use this calculator
Enter the in-place area and the compacted lift depth in metric units. The calculator returns compacted (in-place) volume, the larger loose volume you order, hauled weight in tonnes, and tipper loads. Choose a rectangle for grading and pads, a trench for pipe and utility backfill, or the gap around a foundation (outer excavation minus footing footprint).
Compaction / shrinkage factor — Loose delivered fill loses 15–25% of its volume once placed and compacted to EN 13286 / EN 1997 density, so order the loose volume, not the in-place volume. Tonnes and truck loads use the loose quantity you actually buy and haul. Bulk densities (delivered loose): clean fill 1.4 t/m³, structural / bank-run fill 1.6, gravel / crushed stone 1.65, sand 1.55, clay 1.5, topsoil 1.25.
Saved Calculations
| Time | Shape | Material | Compact m³ | Loose m³ | Tonnes | Trucks | Cost |
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How to Calculate Fill and Backfill (Metric)
Backfill is delivered loose but specified compacted, so the ordered quantity always exceeds the excavation. Measure the in-place area and the required compacted lift depth, choose the delivered material, then set the shrinkage factor for that soil and compaction effort. For trenches and footing backfill, allow over-dig for the side-slope batter when sizing the area — net earthwork balance can be checked with the cut and fill calculator and the excavated hole with the excavation volume calculator.
Formulas
Compacted volume = L × W × depth (m³, no division needed). Loose volume to order = compacted volume × (1 + shrinkage%). Hauled weight = loose volume × bulk density (t/m³), kg = tonnes × 1,000. Truck loads = ceil(loose volume ÷ 10 m³). Foundation backfill area = outer L × W − foundation L × W, then × depth.
FAQ
Why order more than the hole? Loose fill loses 15–25% of its volume when compacted to EN 13286 / EN 1997 density, so you buy and haul the loose volume — weight and truck counts here are based on it.
How many m³ per truck? A standard dump truck carries ~10 m³, a large tipper ~14–16 m³. Heavy gravel may reach the legal axle-weight limit before the box is full.
Aggregate or topsoil specifically? For priced crushed-stone sub-base use the gravel & aggregate calculator; for planting depths and bagged amounts use the topsoil & mulch calculator. If the void is filled with concrete instead of soil, size it with the concrete slab calculator.
Ordering tips
Delivered loose fill across the EU in 2025 typically runs €12–22/t for clean structural fill, €18–35/t for crushed stone 0/32 or 0/63, and €25–50/m³ for screened topsoil — short-haul delivery often costs more than the material itself, so price by the load (about €250–400 per 10 m³ tipper in most markets). The single biggest estimator mistake on backfill is ordering the in-place volume instead of the loose-delivered volume: a 25% shrinkage means a 100 m³ hole needs 125 m³ on the ticket. For trench backfill, also remember EN 1610 / national OSH rules for the slope above the pipe zone — the trench at grade is wider than the bedding, so cross-check with the excavation volume calculator before you order tippers.
