Work out asphalt quantity instantly with clear inputs, formula shown and shareable results.
Asphalt is bought by weight and laid to a thickness, so the bridge between them is compacted density, about 2400 kg/m³ for dense bituminous macadam. The spread rate in kilograms per square metre, thickness in metres times density, is the figure the paving crew checks against delivery tickets.
Spread rate
kg/m² = thickness m x compacted density
Tonnage
Tonnes = area x spread rate x (1 + wastage) / 1000
kg/m² = thickness m x compacted density. Asphalt is bought by weight and laid to a thickness, so the bridge between them is compacted density, about 2400 kg/m³ for dense bituminous macadam.
It is the only real-time control on thickness. Comparing tonnes delivered against area paved catches a layer running thin before the job is finished and cored.
This calculator takes 4 inputs: Area to surface, Compacted layer thickness, Compacted density, Wastage allowance. The pre-filled defaults are a realistic worked example — replace them with your own site or project figures.