Asphalt Tonnage Calculator
Tonnes of asphalt to order for a driveway, path or road from its size, compacted thickness and density, with the number of truckloads.
Results
What this tool does
Asphalt is sold by weight, not volume, and the thickness that matters is after rolling: the loose mat goes down roughly 20 to 25 % thicker and is compacted to the design thickness. Compacted hot-mix asphalt weighs about 2.3 to 2.4 tonnes per cubic metre depending on the stone and binder, so each square metre at 50 mm takes about 117 kg. Domestic driveways commonly have a 40 to 70 mm surface over a compacted granular base, while roads use several layers. The waste allowance covers edges, uneven sub-base and what is left in the truck; ask the plant for the exact density of the mix you order.
Formula
tonnes = length × width × thickness × density × (1 + waste)
Variables
| Symbol | Meaning | Unit |
|---|---|---|
ln | Length | m |
wd | Width | m |
th | Compacted thickness | mm |
dn | Compacted density (hot mix about 2.35) | t/m³ |
wp | Waste allowance | % |
tc | Load per truck | t |
T | Asphalt to order | t |
V | Volume | m³ |
AR | Area | m² |
RT | Spread rate | kg/m² |
TK | Truckloads | — |
Worked example
- Length20 m
- Width5 m
- Compacted thickness50 mm
- Compacted density (hot mix about 2.35)2.35 t/m³
- Waste allowance5 %
- Load per truck20 t
- Asphalt to order12.34 t
- Volume5.00 m³
- Area100.0 m²
- Spread rate117.5 kg/m²
- Truckloads1
Limitations
- Always order a little more material than the calculated quantity. Cuts, breakage and pattern matching create waste that depends on the shape of the job.
- Density changes with temperature, moisture and composition. Use a value from the supplier's data sheet whenever precision matters.
- The result is an estimate based only on the values you type. Real situations often include factors this calculator does not know about.