This asphalt calculator works out how many tons of asphalt a driveway or other area needs. It multiplies the length, width and thickness of the area to get a volume, then multiplies that volume by the density of your mix to get a weight in tons.
Start by measuring the area in feet and the thickness in inches. You will also need the density of the asphalt mix you plan to buy, which is printed on the product label. Enter these figures and the calculator shows the volume and the amount of asphalt you need.
How to use the asphalt calculator
- Measure the length of the area in feet and enter it in the Length box.
- Measure the width of the area in feet and enter it in the Width box.
- Enter the planned thickness of the asphalt in inches.
- Optionally, enter an extra percentage to cover spills and uneven ground.
- Enter the density of your asphalt mix in pounds per cubic foot, taken from the label of the product you buy.
- Read the Volume and Asphalt results and use the tonnage to order your material.
The formula
- Cubic feet = length × width × thickness, with lengths in feet (inches ÷ 12)
- Cubic yards = cubic feet ÷ 27 (a cubic yard is 3 ft × 3 ft × 3 ft)
- With the extra: multiply by (1 + extra % ÷ 100)
- Weight (lb) = cubic feet × density (lb per cubic foot); short tons = lb ÷ 2,000
Worked example
The figures below are made up to show the maths. They are not current prices, rates or product figures.
| Length | 50 ft |
|---|---|
| Width | 12 ft |
| Thickness | 3 in |
| Extra for spills and uneven ground | 5% |
- Volume 5.83 cubic yards
- Volume 157.50 cubic feet
- Asphalt: enter the density of your mix.
The calculator does not assume a density, so the example above stops at volume. As an illustration only: if your mix weighs 145 lb per cubic foot, 157.5 cubic feet × 145 = 22,837.5 lb, which is 11.42 short tons. Use the density printed on your supplier’s ticket.
Tips for an accurate answer
- Use the density printed on the label of your specific mix, because mixes differ.
- Measure length and width at more than one point and use the largest figures if the area is irregular.
- Add an extra percentage if the ground is uneven or if you expect some loss during spreading.
- Check that your thickness is in inches, since entering feet or centimeters will give a wrong result.
- Confirm with your supplier how they sell asphalt, whether by the ton or another unit, before ordering.
Questions people ask
Can this asphalt calculator work from square feet?
This calculator needs length and width in feet, and thickness in inches, so it works from the dimensions rather than a square footage figure alone. If you know the area in square feet, you still need the thickness to find the volume. Enter the length and width that make up that area.
What formula does this asphalt calculator use?
The calculator multiplies length, width and thickness to find the volume in cubic feet, then converts to cubic yards and works out the weight from the mix density. An optional extra percentage can be added to the volume. The steps are shown on the page for you to check.
Can I use this calculator for hot mix asphalt?
You can use it for any asphalt mix as long as you enter the density of that mix from its label. Hot mix and other types can have different densities, so the density you enter should match the product you buy. The calculator itself does not depend on the mix type.
What do I need to enter in this asphalt calculator?
You enter the length and width of the area in feet, the thickness in inches, and the density of your asphalt mix in pounds per cubic foot. You can also add an optional extra percentage for spills and uneven ground. The density should come from the label of the product you plan to buy.
How does the calculator work out the tonnage?
The calculator first finds the volume by multiplying length, width and thickness, converting inches to feet. It then multiplies the volume by the density to get a weight in pounds, and divides by 2,000 to give short tons. If you added an extra percentage, that is applied to the volume before the weight is worked out.
Why does the volume show in both cubic feet and cubic yards?
Cubic feet is the direct result of the measurements, while cubic yards is often how asphalt is discussed or ordered. The calculator divides cubic feet by 27 because a cubic yard is 3 feet by 3 feet by 3 feet. Both figures describe the same volume.
What if I do not know the density of my asphalt mix?
The density should be listed on the product label or data sheet from your supplier. Without it, the tonnage result will not be accurate, so ask the supplier for the figure before you calculate. Do not guess the value.
Should I add an extra percentage?
An extra percentage helps cover spills, waste and uneven ground, which are common when spreading material. If the ground is level and you expect little loss, you can leave the box empty. For a worked case, a 5% extra on a 50 ft by 12 ft area at 3 inches gives 5.83 cubic yards.
How do I find the weight of an asphalt slab or block?
Find the volume in cubic feet, then multiply by the density of your mix in pounds per cubic foot. Divide the pounds by 2,000 to get short tons. This calculator does those steps once you enter the density from your supplier or the mix data sheet.
How many cubic yards are in a ton of asphalt?
It depends on the density of your mix. Divide 2,000 pounds by your density in pounds per cubic foot to get the cubic feet in one short ton, then divide by 27 to get cubic yards. Enter your supplier’s density figure and the calculator shows the volume and tonnage for your area.
Sources
- 1 foot = 0.3048 metre exactly, so 1 inch (a twelfth of a foot) = 2.54 cm. Source: NIST, Revised unit conversion factors (the international foot).
- 1 yard = 0.9144 metre (3 feet). Source: NIST, NIST Guide to the SI, Appendix B.8: Factors for units listed alphabetically.
Density of your asphalt mix: type it from the label of the product you buy. We do not assume a figure.
An estimate from the numbers you enter, worked out with the formula shown. Check quantities with your supplier before you order. Formulas and examples reviewed 24 Oct 2026. Read the disclaimer