About this tool Calculate earthworks cut and fill volumes from existing and proposed ground levels. The tool determines whether the operation is a cut (excavation) or fill (import), and applies soil-specific swell or shrinkage factors to give you the volume you actually need to plan for.
Seven soil types are included — clay, sandy clay, sand/gravel, chalk, topsoil, soft rock, and made ground — each with industry-standard swell and shrinkage factors based on CESMM and UK earthworks practice.
For cut operations, the loose (excavated) volume tells you how many lorry loads to plan for disposal. For fill operations, the order volume tells you how much material to import to achieve the required compacted fill.
How to use this tool 1. Enter the existing ground level — in m AOD from your site survey.
2. Enter the proposed formation level — from the design drawings. Lower than existing = cut, higher = fill.
3. Enter the plan area — in m². For irregular areas, break into zones and calculate each separately.
4. Select the soil type — this determines the swell (cut) or shrinkage (fill) factor applied.
Technical information Bank volume = |depth change| × plan area
Cut (loose volume) = bank volume × swell factor
Fill (order volume) = bank volume ÷ shrinkage factor
Swell factors represent the volume increase when material is excavated from its in-situ (bank) state. Shrinkage factors represent the volume decrease when loose material is compacted to its final state.
Limitations This tool assumes uniform depth change across the entire area. For sites with variable topography, use a grid-based approach or break the site into zones with different average depth changes.
Swell and shrinkage factors are approximate industry values. Actual factors depend on soil grading, moisture content, compaction method, and degree of compaction achieved. Always verify with trial compaction on site.
The tool does not account for topsoil strip, subsoil separation, or waste classification. Plan these operations separately.
Revision history 21 April 2026: Initial release
Disclaimer This tool is provided for educational and general information purposes only. It is not a substitute for professional engineering advice, design or verification.
Diggy and its contributors are not licensed engineering consultants and no results generated by this tool should be used directly for construction, design or safety-critical decisions.
All values and outputs are based on published empirical correlations and should be independently checked and confirmed by a qualified geotechnical engineer before use.
By using this tool, you accept full responsibility for how you interpret and apply the information provided.
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