DIY Cost Tools
Excavation Calculator
CONSTRUCTION CALCULATOR
Estimate in-place excavation volume, loose volume after swell, truckloads, and volume-based cost.
How it works
Rectangular in-place volume is converted to cubic yards. Swell accounts for soil expansion after digging, and loose volume determines truckloads and volume-based cost.
Formula
Bank yd³ = length × width × depth ÷ 27
Loose yd³ = bank yd³ × (1 + swell)
Important limits
- Soil swell varies widely with material, moisture, handling, and compaction.
- Truck rated capacity may be limited by weight before volume.
- Slopes, shoring, access, utilities, dewatering, disposal rules, and contaminated soil are not included.
Frequently asked questions
What is bank volume?
It is material volume in its original undisturbed location before excavation.
Why does loose volume increase?
Excavated particles no longer fit together as tightly, so the same material occupies more space.
Planning excavation volume
Calculate from the intended finished dimensions, but account for side slopes, working clearance, uneven grade, and over-excavation where the project requires them. A trench or pit with sloped sides contains more material than a simple rectangular shape with the same bottom dimensions.
Excavated soil usually occupies more volume after it is loosened. This “swell” affects truck counts, stockpile space, and disposal costs, while backfilled soil may compact to a smaller volume. Soil type and moisture can change both weight and swell, so local contractor or geotechnical values are preferable for large projects. Before digging, verify utility locations, permits, shoring requirements, and safe slope rules; the geometric estimate is not a substitute for an excavation safety plan.
Review notes
The model uses rectangular bank volume, a user-entered swell factor, and whole-load rounding. Last reviewed September 30, 2026.