How to use this asphalt calculator
- Units, choose Feet or Metres for the length and width of your area.
- Length and width, enter the size of the driveway or lot you want to pave.
- Depth, enter how thick the asphalt should be, in inches (Feet mode) or centimetres (Metres mode).
- Density, leave it at 145 lb per cubic foot or set your supplier's figure.
- Read the cubic yards, cubic metres and tons of asphalt, they update instantly as you type.
Nothing is submitted or stored: your measurements never leave your device.
How to calculate asphalt
Asphalt volume is just area multiplied by depth. First find the area by multiplying length × width, then multiply that by the depth to get a volume. The trick is keeping the units consistent: this calculator converts your depth (entered in inches or centimetres) into the same unit as your length and width before working out the cubic feet.
To turn that volume into a weight you can order, multiply the cubic feet by the density of the asphalt. Compactedhot-mix asphalt weighs about 145 lb per cubic foot, so the tons figure is simplycubic feet × 145 ÷ 2000 (there are 2000 lb in a US ton). The tool also shows the volume incubic yards (27 cubic feet to a yard) and cubic metres (about 35.31 cubic feet) so you can match however your supplier quotes the job.
It is always wise to add about 5 to 10% extra on top of the calculated tonnage. Some material is lost to compaction, an uneven sub-base soaks up more than a flat one, and a little spare beats running short mid-pour. So a 20 ft × 10 ft driveway at 3 inches deep works out to roughly 1.85 cubic yards, or about 3.6 tons before you add a margin.
A note on asphalt density
Density is not fixed. Different mixes, aggregate sizes and degrees of compaction all change the weight per cubic foot, and most hot-mix asphalt falls somewhere between 140 and 150 lb per cubic foot. That is why the tons figure here is an estimate. If your supplier quotes a density or a tons-per-cubic-yard value, type it into the density box for a sharper number, and always confirm the final order with them before paving.
Frequently asked questions
How do I calculate how much asphalt I need?
Multiply length by width to get the area, then multiply by depth to get the volume in cubic feet. Multiply the cubic feet by the density (about 145 lb per cubic foot) and divide by 2000 to get US tons. This calculator handles it all for you.
How much does asphalt weigh per cubic foot?
Compacted hot-mix asphalt weighs roughly 140 to 150 lb per cubic foot. This tool uses 145 by default, and you can change the density if your supplier quotes a different figure.
How thick should an asphalt driveway be?
A residential driveway is usually 2 to 3 inches of asphalt over a gravel base, while parking lots and heavier-traffic areas often need 3 to 4 inches or more.
Should I order extra asphalt?
Yes, add roughly 5 to 10% on top to allow for compaction, an uneven sub-base and waste. A little spare beats running short mid-pour.
Is my data uploaded?
No, everything is calculated on your device and nothing is sent anywhere.