BuildTrue
A Mississippi Maple company

Gravel and topsoil estimator

Enter the bed or path size and depth. The estimator returns volume with waste, weight at a stated density, and the number of 25 kg bags, so you can compare bulk delivery with bagged product.

Estimator

Formula: volume = length x width x depth in metres. Volume with waste = volume x (1 + waste / 100). Density stated: about 1.6 tonnes per cubic metre for gravel, which varies by stone type and moisture. Weight = volume with waste x 1.6. Bags = ceiling of (weight in kg / 25). One cubic metre equals 1.30795 cubic yards.

Worked example: Length 5 m, width 2 m, depth 50 mm, waste 10 percent. Volume = 5 x 2 x 0.05 = 0.50 cubic metres. With waste = 0.55 cubic metres, which is 0.72 cubic yards. Weight = 0.55 x 1.6 = 0.88 tonnes. Bags = 880 kg / 25 kg = 35.2, rounded up to 36 bags.
Estimates only. Density and compaction vary by material and supplier. Confirm the density and delivery unit with your supplier before ordering.

Frequently asked questions

How deep should gravel be?

Common planning depths are about 50 mm for paths and decorative beds and 100 mm or more for driveways over a compacted base. Enter the depth your design calls for; this estimator does not design the base.

Why does the weight matter if I buy by volume?

Bulk yards often sell by the tonne while projects are planned by volume. The weight estimate at the stated density lets you compare a bulk quote with bagged product and check delivery limits.

Back to all BuildTrue estimators, including concrete, drywall, deck, framing, and the bid helper