Excavation Volume Calculator
Calculate the volume of earth to be excavated for a foundation, pond, or grading project in cubic yards.
How to use this tool
- Enter excavation length, width, and depth in feet.
- The calculator returns volume in cubic feet, cubic yards, and estimated truck loads.
- Account for soil swell (excavated soil expands by 20–30% in volume).
Estimate excavation volume and truck loads before starting a foundation or grading project.
⚠ This tool provides general estimates for education only and is not financial, tax or legal advice. Figures may not reflect your situation — verify with a qualified professional.
Formula
Volume (ft³) = length × width × depth
Volume (yd³) = ft³ ÷ 27
Truck loads = ⌈yd³ ÷ 10⌉
How it works
The calculator computes the volume of a rectangular excavation by multiplying its three dimensions in feet to get cubic feet, then converts to cubic yards (the industry-standard unit for earthwork) by dividing by 27 (since 1 yd = 3 ft, so 1 yd³ = 27 ft³). Truck loads are estimated assuming a standard 10-cubic-yard dump truck.
This method assumes a flat-bottomed, vertical-sided rectangular cut. Real excavations with sloped walls (battering), irregular shapes, or stepped footings will have different volumes; a soil swell factor of 15–30% should also be added for haulage because excavated soil occupies more volume than in-situ material.
Worked example
- Volume = 30 ft × 20 ft × 4 ft = 2,400 ft³.
- Convert to cubic yards: 2,400 ÷ 27 ≈ 88.89 yd³.
- Truck loads = ⌈88.89 ÷ 10⌉ = ⌈8.889⌉ = 9 loads.
Volume: 2,400 ft³ / 88.89 yd³; Truck loads: 9
Common mistakes to avoid
- Entering depth in inches instead of feet, understating volume by 12x and drastically underestimating truck loads.
- Forgetting bulking factor: excavated soil expands 20-30% in volume once disturbed, so the hauled volume is greater than the in-situ calculation.
- Using a flat average depth on sloped sites rather than accounting for variable cut depths across the excavation footprint.
Key terms
- Cubic yard (yd³)
- The standard unit for bulk earthwork in North America. One cubic yard equals 27 cubic feet and weighs roughly 1.1–1.4 tons depending on soil type.
- Swell factor
- The percentage increase in volume when soil is excavated and loosened. Compact clay may swell 30–40%, while sandy soil swells 10–15%.
- Bank measure
- The volume of soil in its undisturbed, in-ground state — what this calculator estimates. Haulage quantities must account for swell.
- Dump truck capacity
- A standard construction dump truck holds approximately 10 cubic yards of material. Super-dump or tri-axle trucks may carry 14–16 yd³.
- Grading
- Shaping the ground surface to a specified slope or elevation. Excavation volume calculations underpin grading cost estimates.
Frequently asked questions
- How do I calculate excavation volume?
- Multiply length × width × depth in feet to get cubic feet. Divide by 27 to convert to cubic yards. A standard dump truck holds about 10–14 cubic yards.
- How many cubic yards fit in a dump truck?
- A standard single-axle dump truck holds about 10 cubic yards. Tandem and tri-axle trucks can carry 14–20 cubic yards.