Soil Swell and Shrinkage Calculator (Bank, Loose and Compacted Volume)

What this tool does

Soil does not keep its volume when it is moved. Dug up, it fluffs up, or swells: a cubic metre in the ground (bank volume) may become 1.25 m³ in the truck. Spread and compacted in a fill, it can end up smaller than it was in the ground. Published tables often give swell of roughly 10-15 % for sand and gravel, around 25 % for common earth, 30-40 % or more for clay and 50 % or more for blasted rock, but the real figure depends on the soil and the moisture, so use values from your geotechnical report where you have them. Haulage is paid and counted in loose volume.

Formula

loose = bank × (1 + swell) · compacted = bank × (1 − shrinkage) · loads = ⌈loose ÷ truck capacity⌉

Variables

Worked example

Limitations

• The result is an estimate based only on the values you type. Real situations often include factors this calculator does not know about.
• The default values are typical reference figures, not measurements of your situation. Replace them with your own data whenever you have it.