Donaldson R F Gravel, Mulch & Soil Calculator
Work out how much material to order for a garden bed, path or driveway — as volume, weight and bags.
How much should I order?
Volume is area × depth. The extra percentage covers material that compacts or settles (gravel and soil settle by roughly 10–15%) and small losses — 10% is a sensible starting point, more for loose materials on uneven ground. Typical depths: 5–8 cm (2–3 in) of mulch on flower beds, 5–10 cm (2–4 in) of decorative gravel on paths, 10–15 cm (4–6 in) for driveways, 15–20 cm (6–8 in) of topsoil for new lawns. Weights use typical densities and vary with moisture and grading, so treat them as estimates and check with your supplier, who will usually sell by the tonne or by the cubic metre/yard. One cubic yard equals 27 cubic feet or about 0.765 cubic metres.