Gravel & Stone Calculator

Volume, weight, and bag/tonne quantities for any aggregate. Supports MOT sub-base, decorative gravel, sharp sand, ballast, and more.

Material

Density: -

Density (t/m³) - override if known

Overage / Waste (%) 10% recommended for paths and driveways to allow for compaction and spillage.

Compaction factor (%) MOT Type 1: add 15-20%. Gravel/decorative: 0% (loose, no compaction). Sharp sand: 10%.

Delivery format

Enter length × width for rectangular areas, or enter area (m²) directly and leave length/width blank.

Name / description Length (m) Width (m) Depth (mm)

For circular areas use: length = diameter, width = diameter × 0.785 (Ï€/4).

Or enter total area directly (m²) - overrides area grid above

Depth (mm)

Material cost per tonne

Delivery (flat fee)

Labour per m² spread

Total Area
-
m²

Volume (inc. waste)
-
m³

Weight (inc. waste)

tonnes

Bulk bags

to order

Area	Dimensions	Area (m²)	Depth	Net vol (m³)	With waste (m³)	Weight (t)

Material	Density

Decorative gravel / pea gravel: 40-50 mm (paths/borders), 50-75 mm (driveways)
MOT Type 1 sub-base: 100-150 mm compacted (domestic drives), 200 mm (commercial)
Decorative slate / chippings: 30-50 mm
Sharp sand (screeding bed): 30-50 mm
Sharp sand (concrete blinding): 50-75 mm
Topsoil (new lawn): 100-150 mm
Topsoil (borders): 150-300 mm
Ballast (concrete sub-base): 100-150 mm

Always allow 10-15% extra for uneven ground, compaction, and wastage
MOT Type 1 compacts by up to 20% - order uncompacted volume, not finished depth
Bulk bags (800 kg - 1 t) suit small/medium jobs. Loose loads suit anything over 2-3 t
A standard tipper lorry carries 15-20 t; a grab lorry suits awkward access
Use a membrane / weed fabric under decorative gravel to suppress weeds
For driveways, SuDS regulations may require a permeable surface - gravel qualifies