Calculate the tonnage and volume of any aggregate – gravel, sand, ballast, MOT or crushed stone.
Multiply length × width × depth to find the volume, then multiply by the material density to get the weight in tonnes. Pick your material above and this calculator does it automatically.
A bulk bag holds around 850 kg. As a rough guide it covers about 10 m² at 50 mm deep, depending on the material.
Compacted sub-bases like MOT Type 1 are the heaviest at around 2.1 tonnes per cubic metre, while loose gravel and topsoil are lighter at 1.4–1.5 tonnes.