Calculate spoil pile footprint, height, and staging area with OSHA setback compliance.
This spoil pile calculator estimates the physical dimensions of an excavated material pile to help plan staging areas and ensure OSHA compliance. It models the pile as a cone based on the loose volume and the angle of repose.
Loose excavated material naturally forms a conical shape. The cone geometry formulas:
The loose volume is larger than the bank (in-ground) volume because soil expands when excavated. The loose volume = bank volume × (1 + swell%/100). This expanded volume determines the pile size.
Per OSHA 29 CFR 1926.651(j)(2), excavated material must be placed at least 2 ft (0.6 m) from the edge of the excavation. The total staging area includes this setback ring around the pile: Total Area = π × (radius + 0.6 m)².
In-situ volume of excavated material
Typical: 25-45\u00B0. Default 35\u00B0 for mixed excavated soil.
Width across the base of the cone
Peak height of the cone
After 35% swell
Ground area covered by the pile
Including 2 ft (0.6 m) OSHA setback ring
Place spoil pile at least 2 ft (0.6 m) from trench edge. Total staging area including setback: 48.76 m².
Reference: OSHA 29 CFR 1926.651(j)(2)