Asphalt quantities: from plan area to tipper loads
Converting area and layer thickness into compacted volume, tonnage and the delivery schedule behind it.
The engineering question
Asphalt is bought by the tonne but drawn by the square metre. How do you order the right quantity and enough deliveries?
Worked example
The figures below were produced by running the Asphalt Quantity Calculator with the same inputs — during the build, from its authoritative engine.
| Tonnage to order | 484.1 t |
|---|---|
| Compacted volume | 200 m³ |
| Tonnage before waste | 470 t |
| Deliveries (20 t) | 25 no |
| Assessment | 200.0 m³ compacted layer weighs ≈ 470.0 t (484.1 t with 3% waste) — plan ≈ 25 20-t deliveries. |
- Compacted volume is plan area × thickness.
- Tonnage is that volume × bulk density, using the supplier's value.
- Add a waste allowance for trimming and joins, then divide by the delivery size.
Sanity check
40 mm of asphalt at 2.35 t/m³ is about 0.094 t per m². Use that as a quick check on any takeoff.
Tools for this problem
These are the EngiMetric calculators that compute the numbers in this topic. Each one shows its formula, its units and its limits rather than returning a bare result.
References & standards
- EN 12697 — bituminous mixtures
- Specification for Highway Works — pavement design
Related problems
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Also: Civil & Structural