Asphalt Calculator
Enter the size of your driveway, lot or patch and the compacted thickness to see how many tons of asphalt to order. Density and price per ton are editable so you can match your supplier.
How to use this asphalt calculator
- Measure the length and width of the surface. For an irregular shape, split it into rectangles and add the results, or find its area with the Square Footage Calculator.
- Enter the compacted thickness you plan to lay. Hot mix compresses when it is rolled, so use the finished thickness.
- Keep the 10 percent extra or change it. Edges, patches and uneven ground use more material than a perfect rectangle.
- Check the density. The default is a common planning figure for compacted asphalt, so replace it if your supplier gives you another one.
- Add a price per ton for a material cost estimate, then press Calculate. Use Copy result or Export CSV to take the numbers to your supplier.
How to calculate how much asphalt you need
Asphalt is ordered by weight, so the calculator first finds the volume of a flat layer and then multiplies by the density.
- Cubic feet = length (ft) x width (ft) x thickness (in) / 12 x (1 + extra % / 100)
- Pounds = cubic feet x density (lb per cubic foot)
- Tons = pounds / 2,000
- Material cost = tons x price per ton
As a rule of thumb, a ton of asphalt at 145 lb per cubic foot covers about 165 square feet at 1 inch thick, because 2,000 / 145 = 13.8 cubic feet and 13.8 / (1/12) = 165 sq ft.
Worked example
A driveway is 20 ft long and 12 ft wide and you want 2 inches of compacted asphalt. Area = 20 x 12 = 240 sq ft. Volume = 240 x (2 / 12) = 40 cubic feet. With 10% extra the volume is 44 cubic feet, which is 1.63 cubic yards. Weight = 44 x 145 = 6,380 lb, or 3.19 tons. At $100 per ton the asphalt itself costs 3.19 x 100 = $319.00.
Suppliers often have a minimum load, so a small job may be priced above this simple figure.
Assumptions & limits
- The surface is flat and the thickness is even. Slopes, drainage falls and crowned surfaces need extra material.
- The default density of 145 lb per cubic foot is an editable planning figure. Mix design and compaction change the real value.
- The price is your own input. The calculator does not look up prices and the cost excludes delivery, base stone, removal and labor.
- This tool gives a material estimate only. A paving contractor decides the base, thickness and mix for your site and climate.
- Tons are US short tons of 2,000 lb. Metric tons are not used in the result.
Frequently asked questions
How do I calculate tons of asphalt?
Multiply length by width in feet, multiply by the thickness in feet (inches divided by 12), multiply by the density in pounds per cubic foot, then divide by 2,000. A 20 ft by 12 ft driveway at 2 inches and 145 lb per cubic foot needs 2.9 tons before any extra.
How much does a ton of asphalt cover?
At 145 lb per cubic foot, a ton covers about 165 square feet at 1 inch thick, or about 83 square feet at 2 inches thick. The figure changes if your supplier uses a different density.
What thickness should a driveway be?
That depends on the base, the soil and the vehicles using it. The calculator uses whatever thickness you enter, so ask a local paving contractor what they recommend.
Why add extra to the order?
Edges, patches and small dips in the base use more material than a flat layer. The calculator starts at 10 percent and you can change it.
Is the result loose or compacted?
The thickness you enter is treated as the finished, compacted thickness. Loose hot mix is thicker before rolling, so ask the supplier how they quote their tons.
Can I use metric units?
Yes. Choose meters for length and width and centimeters for thickness. The result is still shown in US tons and cubic yards.
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Last updated: November 2026