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Calculator · Sheet T-202

Excavation volume calculator

A pit, basement or pad excavation with vertical or sloped sides: bank volume, loose volume, tonnes and truckloads.

Excavation volume · Sheet T-202Metric
m
m
m
H per 1V
0 = vertical walls (shored or boxed). 1 = 1H:1V.
m³ loose
Heaped loose capacity of your trucks.
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Estimates only. Check quantities against the drawings and your supplier before ordering.

STA 0+120How it works

For sloped sides the calculator uses the prismoidal formula: V = D ÷ 6 × (Abottom + 4 Amid + Atop), where each side grows by the slope times the depth. With vertical walls it is simply length × width × depth.

Loose volume = bank volume × swell ratio for the material. Tonnes use the midpoint of the published bank weight range. Truckloads = loose volume ÷ truck box, rounded up.

STA 0+240Assumptions and sources

Swell ratios per bank cubic metre: clay 1.43, loam 1.25, sand or gravel 1.11, blasted rock 1.501111. Bank densities are the midpoints of the field manual’s published ranges (converted from lb/yd³)1111. These are planning averages; moisture changes both.

Worker protection

Any excavation a worker enters deeper than 1.2 m (1.5 m in Alberta) must be sloped, benched, shored or boxed23. See trench safety by province.

Questions people ask

How do I calculate excavation volume with sloped sides?

Work out the bottom area and the top area (each side grows by the slope ratio times the depth), then use the prismoidal formula: depth ÷ 6 × (bottom + 4 × middle + top). The calculator does this for you.

How many truckloads is my excavation?

Convert the bank volume to loose volume with the swell ratio, then divide by the heaped capacity of one truck and round up. Clay bulks the most, about 1.43 times its bank volume1.

What is the difference between bank and loose volume?

Bank volume is the ground in place, before it is dug. Loose volume is the same material in a truck or stockpile, after it has bulked up.

Sources

  1. FM 5-434 Earthmoving Operations, Chapter 1, Tables 1-1 and 1-2U.S. Department of the Army (field manual; hosted copy on GlobalSecurity.org) · FM 5-434 (2000)
  2. O. Reg. 213/91 Construction Projects, Part III Excavations (ss. 222-242)Government of Ontario (e-Laws) · consolidation current to 2026-09-21
  3. Alberta OHS Code (Alta Reg 191/2021), Part 32 Excavating and TunnellingGovernment of Alberta (OHS legislation search) · retrieved 2026-09-24