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).
- Project type, pick residential driveway, commercial lot or patch/cold-mix repair to fill in a typical thickness and density, or leave it on Custom and type your own figures.
- 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.
- Add another section for every driveway or lot area in the job, each one gets its own volume and tonnage, and a combined total appears once you have more than one.
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. Compacted hot-mix asphalt weighs about 145 lb per cubic foot, so the tons figure is simply cubic feet × 145 ÷ 2000 (there are 2000 lb in a US ton). The tool also shows the volume in cubic 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.
The Project type preset is a shortcut for the two numbers that vary most between jobs: thickness and density. Residential driveway fills in 2.5 inches of hot-mix asphalt at 145 lb per cubic foot, commercial lot / heavy traffic fills in 3.5 inches at 148 lb per cubic foot, and patch / cold-mix repair fills in 2 inches at 130 lb per cubic foot, cold-mix tends to compact less densely than hot-mix and varies more by brand, so check the product bag if you are using a packaged patch material. These are general planning figures, not a spec from any one supplier or mix design, and both the depth and density boxes stay editable after you pick a type, so your own numbers always win. Add a section for every driveway or lot area with a different size or spec, each section keeps its own project type, and the combined total adds up every section's own volume and tonnage.
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.
What do the project type presets use?
Residential driveway fills in 2.5 inches of hot-mix asphalt at 145 lb per cubic foot, commercial lot fills in 3.5 inches at 148 lb per cubic foot, and patch or cold-mix repair fills in 2 inches at 130 lb per cubic foot. These are general planning estimates, not one supplier or mix design, so edit the thickness and density if your paver quotes different figures.
Can I calculate asphalt for more than one section at once?
Yes. Use Add another section to enter a second, third or further driveway or lot area, each with its own length, width, depth and project type. The tool shows every section's own volume and tonnage plus a combined total for the whole job.