Excavation Calculator
Calculate cubic yards of excavation, cost, and haul-away truck loads for any digging project. Adjust for soil type and swell factor.
Last updated 2026-08-21
What Is a Excavation Calculator?
An excavation calculator figures out how much dirt you will dig out of a hole in cubic yards, which is how excavators and haulers price their work. You enter the length, width, and depth of the excavation. It is the first number you need to get a quote and arrange haul away.
How It Works
Volume = Length × Width × Depth. Cubic yards = Volume ÷ 27.
Example
A 20 ft × 10 ft × 3 ft excavation is 600 cu ft = 22.2 cubic yards.
How to Calculate
- Measure the length, width, and depth of the hole in feet. A 20 ft by 10 ft by 3 ft excavation is 600 cubic feet.
- The tool converts cubic feet to cubic yards by dividing by 27, giving 22.2 cubic yards.
- Give this yardage to your excavator for a price quote and to your hauler to size the trucks.
- Account for soil swell. Dug soil loosens and expands about 10 to 30%, so hauled volume can exceed the in place volume.
- For deep or unstable soil, factor in sloped or benched walls, which add volume beyond the simple box shape.
Common Soil Swell Factors
| Soil Type | Swell Factor |
|---|---|
| Sandy soil | 10 to 15% |
| Loam / topsoil | 15 to 20% |
| Clay | 20 to 30% |
| Rock (blasted) | 30 to 50% |
| Gravel | 10 to 12% |
Sources
Frequently Asked Questions
Why is excavation measured in cubic yards?
Excavators and hauling are priced by the cubic yard, so it is the number to give your contractor.
Should I add a swell or compaction factor?
Dug soil swells about 10–30% when loosened. Ask your hauler whether their price accounts for that.
Do I need a bench or slope?
For deep or unstable soil, OSHA requires sloped or benched walls — that adds volume beyond the box shape.
Estimate the cost with the Excavation Cost Calculator. Also try: Trench Calculator, Backfill Calculator or browse Excavation Calculators