Asphalt Calculator: measuring notes and method
Separate different courses
Calculate layers with different mixes or thicknesses as separate items so each quantity can be matched to the order.
Keep tonnage and area distinct
Mass is the quantity for a weight-based order. Surface area alone cannot determine tonnage without thickness and density. Delivery rounding and placing losses should remain visible as separate decisions.
Formula
Volume = length × width × depth × (1 + waste ÷ 100). Mass = volume × density.
Worked examples in metric and imperial units
Illustrative values match Reset example and stay fixed when you edit the calculator. Both columns describe the same calculation; converted inputs are rounded.
Metric worked example
- Length
- 6 m
- Width
- 4 m
- Finished depth
- 50 mm
- Bulk density
- 2,400 kg/m³
- Waste allowance
- 10 %
Material weight: 3,168 kg
Imperial worked example
- Length
- 19.685 ft
- Width
- 13.1234 ft
- Finished depth
- 1.9685 in
- Bulk density
- 149.8271 lb/ft³
- Waste allowance
- 10 %
Material weight: 6,984.2445 lb
Follow the calculation
Lengths in this working are in metres.
- Net volume = 6 × 4 × 0.05 = 1.2 m³.
- Allowance multiplier = 1 + 10 ÷ 100 = 1.1.
- Mass = 1.32 m³ × 2,400 kg/m³ = 3,168 kg.
Unit conversions
1 m³ = 1,000 L ≈ 1.30795 yd³. One cubic yard is 27 ft³.
For metric tonnes, divide kg by 1,000. For US short tons, divide lb by 2,000; a long ton is 2,240 lb. Confirm your supplier’s unit.
Reviewed 19 October 2026. How calculations are checked · Report a correction