Excavation Volume Calculator — ft to yd³, truck loads, cost
How to use this calculator
Pick the excavation shape — rectangular pit, trapezoidal (battered/sloped sidewalls per OSHA), circular shaft, or utility trench — then enter dimensions in feet, inches and fractions and select the soil class to load its swell factor. Bank volume (in-place, undisturbed) and loose volume (after excavation, expanded) are reported in cubic yards along with hauled weight and truck loads.
Swell factor — excavated soil bulks up as it loosens. Typical bank→loose swell: clay 30-40%, sand/gravel 10-15%, topsoil 20-30%, rock 40-60%. Always size haul trucks off loose volume. Cost — disposal priced per cubic yard or per truck load (haul + tipping fee). For fill placed back into the same excavation, see the cut and fill calculator for the net haul-off after compaction.
Saved Calculations
| Time | Shape | Soil | Bank yd³ | Loose yd³ | Trucks | Cost |
|---|
How to Calculate Excavation Volume
Earthwork is bid on two volumes: bank (in-place, undisturbed) and loose (the swelled volume that actually rides in the truck). This tool computes both in cubic yards for a rectangular pit, a trapezoidal cut with battered walls, a circular shaft (caisson, well, pier hole), and a utility trench. Enter feet, inches and eighth-inch fractions; the soil class sets the swell factor and an approximate haul weight so you can check truck axle limits as well as box volume.
Swell factor and over-excavation
Excavated soil bulks up as it loosens, so Loose Volume = Bank Volume × (1 + Swell%). Typical bank→loose swell: clay 30-40%, sand/gravel 10-15%, topsoil 20-30%, rock 40-60%, shale 35-45%. Two field allowances are not auto-added: trench over-dig for OSHA sloping or shoring (use the trapezoidal shape with the real top width), and a 5-10% line-and-grade waste on machine work. When that spoil is later returned, the compaction shrink (~10-20%) means you import more bank yards than you removed — size that with the fill and backfill calculator, and net cut against fill across a site with the cut and fill calculator.
Formulas
Rectangular / Trench: L × W × D ÷ 27 = yd³. Trapezoidal: L × ((Top W + Bottom W) ÷ 2) × D ÷ 27. Circular: π × r² × D ÷ 27. Hauled weight uses an approximate in-bank unit weight (sand/gravel ≈ 2,600 lb/yd³, clay ≈ 2,800 lb/yd³, rock ≈ 4,000 lb/yd³); 1 ton = 2,000 lb. Loose volume drives the truck-load count.
FAQ
How many truck loads for a basement? A 30×40×8 ft dig = 356 yd³ bank; at 25% swell = 444 yd³ loose; at a 10 yd³ box = 45 loads. Why use the trapezoidal shape? OSHA 29 CFR 1926 Subpart P requires sloped or shored walls below 5 ft (≈1.5H:1V for Type C soil), which adds real volume — enter the wider top width to capture it. Bank vs loose volume? Bank is undisturbed in-ground soil; loose is the same soil after digging, expanded by the swell factor. Granular backfill or stone bedding? Price aggregate separately with the gravel and aggregate calculator, screened topsoil with the topsoil and mulch calculator, and concrete in shafts with the concrete pier calculator.
On the jobsite
2025 USA pricing runs $30–75/yd³ for machine excavation in average soil, $80–150/yd³ in rock, plus $15–35/ton tipping at most C&D landfills; truck hauling adds $250–500 per 10-yd³ load round-trip. The #1 estimator mistake on this trade is quoting against bank volume instead of loose — a 100 yd³ basement at 30% clay swell is 130 yd³ in the truck, so the haul bill is 30% bigger than the dig sheet. Two other things to budget: OSHA sloping (29 CFR 1926 Subpart P) on any dig over 5 ft adds real spoil — model it with the trapezoidal shape, not a flat overdig number — and a locate stand-by day from 811/utility marking before you break ground. For backfill against the same foundation use the fill and backfill calculator; for the slab over a finished cellar see the concrete slab calculator.
