Gravel Calculator
Estimates gravel volume and tonnes needed for a road base or landscaping area.
Enter Values
Before you rely on this: First-pass guide only. Verify safety-critical or regulated work against the relevant standards, your project requirements and a qualified professional.
How to use this calculator
- Enter the length, width and depth.
- Press Calculate.
How it works
Volume = length × width × depth; weight ≈ volume × 1.5 tonnes per m³ for gravel.
Worked example
4 × 5 × 0.1 m. = 2 m³ ≈ 3 tonnes.
Common mistakes
- Entering depth in the wrong unit — a 50 mm layer is 0.05 m, not 0.5 m.
- Ordering exact volume; add about 10% for compaction and spread.
Frequently asked questions
How much gravel do I need?
Multiply area by depth for volume, then by density (gravel is roughly 1.5 tonnes per m³) for the weight to order.
How deep should a gravel layer be?
About 50 mm for a top dressing, 75–100 mm for paths, and 100–150 mm or more over a sub-base for driveways.
How do I convert cubic metres to tonnes?
Multiply by the material density — gravel is roughly 1.5 t/m³, so 2 m³ ≈ 3 tonnes. Suppliers' figures vary with moisture and stone size.
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Cite this tool
Zerdly. (2026). Gravel Calculator. Retrieved from https://www.zerdly.com/tools/gravel-calculator/
Tip: Enter any known values to calculate the remaining results.
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