How much gravel do I need?
Gravel, slate, sub-base, sand or soil — work out the area and depth, and get the volume, the weight in tonnes, and the number of bulk bags. Aggregate is sold by weight, so the depth matters as much as the area. Free, no sign-up.
A guide, not a guarantee. Densities are typical figures — your supplier's exact weight per cubic metre may differ, especially for wet or graded material. Aggregate beds down as it's compacted, so order a little over rather than under. For a gravel drive you'll want a compacted sub-base and a membrane underneath, both extra. Nothing you type leaves your browser.
Area, depth, volume, then weight.
Volume first. Length times width gives the area, and times the depth gives the volume in cubic metres. Depth is the part people skip — five centimetres versus ten doubles the order. Use the compacted depth you want to end up with.
Then convert to weight. Aggregate is sold by weight, not volume, so we multiply the volume by the material's density. Gravel and shingle are around 1.5 tonnes per cubic metre; MOT Type 1 sub-base is heavier at about 2.0; topsoil is lighter. Pick the closest material, or enter your supplier's exact density.
Bulk bags or loose. A "bulk bag" or dumpy bag is usually 800 kg, though some yards sell them as a full tonne — check before you order, as it changes the bag count. We round bags up. For a big job, loose by the tonne off a tipper is cheaper than bags.
How deep for what. Decorative gravel over a prepared base is 4–5 cm — deeper and it's hard to walk on and rake. A sub-base under a drive or patio is 10–15 cm of MOT Type 1, compacted in layers. A bedding sand layer under slabs is around 5 cm.
What this leaves out. A weed membrane, edging or gravel boards, the compacting plate hire, and the cost of digging out and removing spoil first are all separate. Order a little over — aggregate settles as it compacts.
Keep every job and its details in one place.
Stead remembers your outdoor jobs, what you laid and when, and what's due next — so the next project starts with the numbers already to hand.