Gravel & Aggregate Calculator

Calculate the tonnes and bulk bags of gravel, aggregate, or sub-base you need — with the correct density for your actual material, not a generic guess. Enter your area and depth, pick your material, and get an instant order list.

Aggregate & Sub-base Planner

Gravel & Aggregate Calculator

Work out the tonnes and bulk bags you need — with the correct density for your actual material, not a generic guess.

Region

Material Different materials weigh different amounts — this sets the density used.

Measure in

Length Width

Diameter

Depth

Driveway gravel: ~50mm. Sub-base: 100–150mm. Decorative: ~40mm.

Bulk bag weight near you

Advanced options

Waste / compaction allowance Loose material spreads and sub-base compacts — a buffer stops you coming up short.

50 mm

5 m × 4 m

Coverage preview

— tonnes

— bulk bags

A planning guide, not a final quote. Tonnages use typical material densities, and bulk-bag weights differ by supplier and region — moisture changes weight too. Please cross-check against your own measurements and your supplier’s actual figures before ordering a bulk delivery, and round up rather than down.

Densities and bag weights vary by supplier. Always confirm quantities locally before you buy.

How to use this calculator

Enter the length and width of your area and the depth you’ll lay, then choose your material — gravel, pea shingle, slate, MOT Type 1 sub-base, sharp sand, and more each have their own density, which is what makes the tonnage accurate. The result gives you tonnes, cubic metres, cubic yards, and the number of bulk bags.

Planning a project? See our guides on how much gravel for a driveway and how deep gravel should be.