Excavation Calculator
How much dirt are you really moving? Excavation volume for pits, trenches and piers — adjusted for soil swell — in truckloads and haul cost, not just cubic feet.
The Dirt You Dig Is More Than the Hole
The trap in excavation is that soil swells when you dig it. A neat hole of 30 cubic yards becomes 37 or more once it is loose in the truck. Order your hauling by the in-ground (bank) volume and you will run short of trucks. This calculator gives both, plus the truckloads and cost that actually matter on site.
Bank vs Loose Volume
Bank volume is the soil in place, undisturbed. Loose volume is the same soil after digging breaks it up and traps air. The increase is the swell or bulking factor:
Typical swell runs about 10 to 25 percent for common soil, higher for heavy clay and much higher for blasted rock. Disposal and trucking are billed on loose volume; backfill compaction works the other way (shrinkage).
Shapes
| Excavation | Volume |
|---|---|
| Rectangular pit | length × width × depth |
| Trench | length × width × depth |
| Circular pier / pit | π × radius² × depth |
Frequently Asked Questions
Which volume do I order trucks for?
Loose volume. The truck carries bulked-up soil, so a 10-yard truck holds about 10 loose yards, not 10 bank yards.
What swell factor should I use?
Sandy soil around 10 to 15 percent, common earth 20 to 25, stiff clay 25 to 40, and rock can exceed 50. Use a soil-specific figure when you have one.
Does this size shoring or slopes?
No. Anything over about 5 feet deep needs proper sloping, benching or shoring per OSHA – this tool sizes volume only, not trench safety.
Related calculators
- Concrete Volume Calculator — concrete to fill the footings you dig.
- Retaining Wall Calculator — for cut-and-retain situations.
- Soil Bearing Capacity Calculator — check the soil at the bottom of the dig.
- All engineering calculators — the full library.