Gravel Calculator
Choose the shape, enter your dimensions, and get base volume, order volume with waste, and estimated gravel weight.
Calculate
Calculate
Measurements convert when you switch units
Result
The formula
Rectangular area uses length × width × depth. Circular area uses π × (diameter/2)² × depth. Trench uses length × trench width × trench depth. Weight = volume × gravel density.
Worked example
- Driveway 12 m × 3 m × 0.1 m → base volume 3.6 m³
- Add 8% waste → order volume 3.6 × 1.08 = 3.89 m³
- At density 1.6 t/m³ → estimated weight 3.89 × 1.6 = 6.22 t
Result: 3.89 m³ to order (about 6.22 t)
How gravel quantity is calculated
The calculator first computes geometric volume, then applies your waste factor and density to estimate transport weight.
Use compacted depth, not loose depth
For road base and driveways, enter target compacted depth. If your supplier gives loose depth guidance, convert before estimating.
Why waste factor matters
Spillage, uneven subgrade, and leveling loss increase real demand. A 5–12% waste factor is common depending on site conditions.
Density changes by aggregate type
Crushed stone, pea gravel, and recycled aggregate have different bulk density. Confirm your supplier’s density for better tonnage estimates.
Interesting facts
1 cubic metre is about 1.308 cubic yards
Metric and imperial deliveries often differ by market. The calculator shows both to reduce ordering mistakes.
Typical gravel density range
Most aggregates are around 1.4–1.8 t/m³. This tool defaults to 1.6 t/m³ for general estimates.
Compaction affects thickness
A loose layer can settle after compaction. If your depth target is compacted, account for that when planning delivery.
Driveways usually need layered construction
Many driveways use separate base and top layers. Calculate each layer volume separately for better costing.
Trenches overrun easily
Trench side collapse and irregular bottoms can increase fill quantity beyond theoretical volume.
Short loads can cost more
Suppliers may charge minimum load fees. Converting volume to tonnes helps optimize haul planning.
Frequently asked questions
Use rectangular mode: length × width × depth, then add a waste factor. For example, 12 × 3 × 0.1 m = 3.6 m³ base volume.
Use compacted design depth for accuracy. If supplier guidance is loose depth, increase delivered quantity accordingly.
Multiply order volume by density: tonnes = m³ × t/m³. Example: 4.0 m³ × 1.6 = 6.4 t.
Flat, well-prepared areas may use 5%. Irregular sites or trench work often need 8–12%.
Yes. Use circular mode with diameter and depth; the calculator applies π(d/2)² × depth.
Yes. Subtract non-gravel sections from total area to avoid over-ordering.
Compaction and void filling reduce loose thickness. This is normal for many aggregates.
Yes, but use the correct density for your stone size and type, and check local drainage layer specs.
References
- Aggregates for concrete and road materials General aggregate characteristics and applications.
- Metric (SI) units guidance Unit system and conversion references.