Excavation Calculator

Calculate excavation volume, truck loads and disposal for trenches and pits.

Please note: Material estimates for planning only. Always confirm quantities against your drawings, local building codes and supplier specifications before ordering. Structural work requires a qualified engineer.

What the Excavation Calculator does

Excavation volume is straightforward geometry, but the volume you haul away is larger than the hole. Disturbed soil bulks up by 20–30% as it loses its compacted structure, and haulage is charged on that loose volume.

Formula

Bank volume = Length × Width × Depth
Loose volume = Bank volume × (1 + Bulking %)
Truck loads = ⌈Loose volume ÷ Truck capacity⌉
Weight = Bank volume × Soil density

Inputs explained

Input	Unit	Required	Notes
Excavation type	one of 2 options	Yes	—
Length	number	Yes	Accepts more than 0.
Length unit	one of 6 options	Yes	—
Width	number	Yes	Accepts more than 0.
Width unit	one of 6 options	Yes	—
Depth	number	Yes	Accepts more than 0.
Depth unit	one of 6 options	Yes	—
Bulking factor	%	Yes	Excavated soil takes more space than in the ground. 20–30% is typical.
Truck capacity	m³	Yes	Accepts 0.1 or more.
Soil density	kg/m³	Yes	Accepts 100 or more.
Disposal cost per m³	selected currency	Optional	Accepts 0 or more.
Currency	one of 10 options	Optional	—

How to use it

Choose Excavation type and Length unit.
Enter Length, Width, Depth and Bulking factor and 2 more.
Optionally add Disposal cost per m³.
Select Calculate.

Worked example

A 10 m trench, 0.6 m wide, 1.2 m deep, 25% bulking, 8 m³ trucks, 1,600 kg/m³ soil.

Length: 10 m
Width: 0.6 m
Depth: 1.2 m
Bulking: 25
Truck: 8

Bank volume 7.2 m³, loose 9 m³ → 2 truck loads, weighing 11.52 tonnes.

Frequently asked questions

What is bulking?

The volume increase when soil is dug out. Compacted ground loosens as it is disturbed, so 1 m³ in the ground becomes 1.2–1.3 m³ on the truck.

Does soil type matter?

Considerably. Sand bulks around 10–15%, clay 25–35%, and rock can exceed 50%.