chuck How the calculation works
Geometric volume (m³) = length × width × depth in millimetres ÷ 1,000. Planned volume = geometric volume × (1 + allowance ÷ 100). Litres = cubic metres × 1,000.
Use the result with care
This assumes a rectangular shape and constant depth. The allowance is your input, not a recommended waste or compaction factor. Volume does not determine dry-material mass, mixing quantities, compaction, load capacity, suitable thickness or design compliance. Irregular shapes need separate measured sections.
Your figures stay in this page
The calculation runs in your browser. These entries are not sent to a calculator service or saved by this tool. Reset returns the form to its starting values.