Excavation Calculator
Enter pit or trench dimensions to get the in-ground (bank) volume, the hauled (loose) volume with soil swell applied, and the truckloads disposal will need.
Last updated: 2026-09-28
How the calculation works
- Bank volume is the geometric hole: length × width × depth divided by 27 ft³/yd³.
- Excavated soil fluffs up — swell converts bank yards to the loose yards the trucks actually haul.
- Truckloads divide loose volume by a common 10 yd³ single-axle dump; scale for your hauler's trucks.
- Weight uses a typical loose mixed-soil density (~2600 lb/yd³) since disposal is often priced per ton.
Formula
Bank yd³ = L × W × D ÷ 27 Loose yd³ = bank × (1 + swell) loads = loose ÷ truck capacity
| Symbol | Meaning | Unit |
|---|---|---|
bank | In-ground (undisturbed) volume | yd³ |
swell | Volume increase after excavation | — |
Worked example
Interpreting the result
Bank vs loose is the distinction that breaks disposal estimates: you dig 13 yd³ but haul 17. Sloped or benched sides (OSHA-required over 5 ft in many soils) add real volume beyond the bottom dimensions — a 1:1 slope on a 3 ft trench nearly doubles the surface width. Over-excavation for bedding and grade correction typically adds 10-20% on top; order disposal accordingly.
Assumptions
- Rectangular trench or pit at bottom dimensions, vertical sides.
- Swell factor per soil type: 15% sand, 25% mixed, 30-40% clay.
- 10 yd³ truck capacity for the load count.
Limitations
- Sloped/benched sides, bedding layers and dewatering volumes are not included.
- Rock excavation has different swell (~50-80%) and hauling costs.
Frequently asked questions
How much does excavated soil swell?
Sand swells ~15%, common mixed earth ~25%, clay 30-40% — measured as loose volume over bank volume. Compacted backfill returns to roughly bank volume.
How many yards are in a truckload of dirt?
Typical single-axle dumps carry 10 yd³; tandems 16-20. Weight limits often bind before volume: 10 yd³ of wet clay at ~3000 lb/yd³ is 15 tons — check the truck's payload.