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Trench Excavation, Spoil and Vehicle Load Calculator

Estimate trench excavation, loose spoil, tonnes or short tons and vehicle loads using metres/cubic metres or feet/cubic yards.

Trench Excavation, Spoil and Lorry Load Calculator

Enter your data

Use consistent units and verify the point or flow direction.

No sign-in
m
m
m
H : 1V
Use 0 for vertical trench sides.
%
m³
m³
t/m³
Inputs are processed in this browser. This calculator does not send project data to a server.
Check before use: This is an independent calculation aid, not approved design information. Confirm inputs, units, coordinate order, tolerances and project conventions before construction or setting out.

Trapezoidal trench volume

Side slope is entered as horizontal movement for each one unit of vertical depth on each side. A 0.25 value means the top extends 0.25 m horizontally per 1 m depth on both sides.

top width = base width + 2 × side slope × depth
volume = length × depth × (base width + top width) ÷ 2

Bulking factor

Excavated material generally occupies a different loose volume than it did in the ground. The correct factor varies with soil type, rock fragmentation, moisture, compaction and handling; the default is only an editable example.

Vehicle loads

The load count is rounded up using loose cubic capacity. In practice payload by mass, highway limits, material density and the operator's safe loading policy may govern before body volume is reached.

Frequently asked questions

What is displacement volume?

It is an optional deduction from gross in-situ excavation for known items occupying trench volume, such as a large pipe or pre-calculated bedding volume.

Should I use tonnes or cubic metres for lorries?

Both can limit a load. This page estimates volume-based loads and separately displays mass from your density assumption. Use the more restrictive verified capacity.

Does the calculator include overbreak?

Only when you include it in the entered dimensions or bulking allowance. Add project-specific working space, overdig and irregularity allowances explicitly.