Asphalt Quantity Calculator

Work out asphalt quantity instantly with clear inputs, formula shown and shareable results.

About Asphalt Quantity Calculator

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.

Formulas

Spread rate

kg/m² = thickness m x compacted density

Tonnage

Tonnes = area x spread rate x (1 + wastage) / 1000

Worked example

With the default values below, Asphalt Quantity Calculator returns Asphalt to order of 63.00. Change any input above and every figure here is recalculated in your browser.

Inputs used

Area to surfaceminimum 0.1 m²: 500 m²
Compacted layer thicknessminimum 5 mm: 50 mm
Compacted densityminimum 500 kg/m³: 2,400 kg/m³
Wastage allowanceaccepts 0–25 %: 5 %

Results

Asphalt to order: 63.00 t
Compacted volume: 25.00 m³
Spread rate: 120.0 kg/m²
Truck loads at 20 tonnes: 4

Step by step

1Values used
2Spread rate
3Tonnage
4Asphalt to order= 63.00 t
5Compacted volume= 25.00 m³
6Spread rate= 120.0 kg/m²
7Truck loads at 20 tonnes= 4

Assumptions and limits

The result is derived only from the 4 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
Figures are rounded for display to 2 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Frequently Asked Questions

How is the Asphalt Quantity figure worked out?

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.

Why is the spread rate checked on site?

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.

What values do I need to enter?

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.