Excavation Volume
Cubic yards of soil for a sloped excavation.
Example
You enter
- Length (ft) 10
- Width (ft) 10
- Depth (ft) 5
- Side-slope angle (deg, 90 = vertical) 90
You get
- Volume 500 ft^3
- Cubic yards 18.52 cy
- Top dimensions 10
- Top width (ft) 10
- Set back (ft) 0
No published worked example is on file for this calculation. It is checked against a hand-worked derivation of its method and an independent reference test.
Details, formula, and sources
Formula or tableVolume = D × (L × W + (L + W) × s + 4 s² / 3), the prismoidal volume of a pit with a constant side slope (setback s = D / tan(angle) per side), for OSHA-compliant slopes (Type A / B / C per OSHA 29 CFR 1926 Subpart P).
Source and editionOSHA 29 CFR 1926 Subpart P (Excavations).
Free accessFree at ecfr.gov.
What governsEstimate. AHJ and licensed structural engineer govern.
API field nameslength_ft, width_ft, depth_ft, side_slope_angle_deg, volume_ft3, cubic_yards, top_length_ft, top_width_ft, set_back_ft
- Soil swell factor user-supplied; typical 25% for clay / 15% for sandengineering practice