About this calculator
Gravel for paths, driveways, patios and drainage, as cubic metres and tonnes, with weed fabric under it.
How it’s calculated
Volume = area × depth. Weight = volume × density (about 1.5–1.7 t per m³ for most gravel).
Worked example
With these inputs:
- Area shape
- Rectangle
- Length
- 6 m
- Width
- 3 m
- Depth
- 50 mm
- Material
- Crushed stone 20 mm
- Extra for settling / compaction
- 5%
the result is:
- Volume
- 0.95 m³
- Area
- 18 m²
- Approx. weight
- 1.56 t
- 25 kg bags
- 63 bags
Tips from the trade
- 40–50 mm of decorative gravel over 100 mm of compacted MOT for paths and drives.
- Edging stops gravel creeping into lawns and beds.
- Suppliers sell by weight, so always check the weight figure.
Common questions
How much does a cubic metre of gravel weigh?
About 1.5–1.7 tonnes, depending on the stone and how wet it is.
How much gravel is in a bulk bag?
A bulk bag holds about 850 kg, covering roughly 10 m² at 50 mm.
Results are estimates for planning and pricing. Check quantities against your drawings, the manufacturer’s data and the Building Regulations before ordering.