Excavation Calculator

Choose the excavation shape and enter its dimensions. Add a bulking percentage to estimate the loose volume of excavated soil.

Your result will appear here after you press Calculate.

How this calculator works

Rectangular pit / trench = length × width × depth

Circular pit = π × (diameter ÷ 2)² × depth

Sloped-side pit = D × [L·W + s·D·(L + W) + (4/3)·s²·D²]

Sloped-side trench = length × D × (bottom width + s·D)

where s is the side slope (horizontal run per 1 vertical) and D the depth. Loose volume = volume × (1 + bulking ÷ 100)

Assumptions and limits

  • Dimensions are for the excavated shape at the bottom (L, W) with sides sloping outwards for the sloped options.
  • Soil bulking varies widely with soil type. Use a value from your geotechnical advice.
  • Shoring, working space, ramps and varying ground levels are not included.

This tool gives an approximate estimate from the values you enter. It is not a substitute for professional engineering design, site inspection, official quotations or applicable building regulations. See the calculator disclaimer.