Asphalt Calculator
Enter the area and paving thickness to estimate how many tons of asphalt (blacktop) you'll need.
To estimate asphalt tonnage, multiply length, width and thickness in feet to get cubic feet, multiply by the mix density (about 145 lb per cubic foot for hot-mix asphalt), then divide by 2,000 to convert pounds to tons. Blacktop is another name for the same hot-mix asphalt.
How to Use This Calculator
Enter the length and width of the area you are paving in feet, then the compacted thickness of the asphalt layer — two inches is common for a residential driveway overlay, three or more for a new base. Choose whether the thickness is in inches or feet.
The mix-density field is pre-filled with 145 pounds per cubic foot, a typical figure for compacted hot-mix asphalt. If your supplier quotes a different density for their specific mix, enter it. The result is the estimated weight of asphalt in tons, which is how it is ordered.
How the Calculation Works
Asphalt is sold by weight, not volume, so the calculation converts your paved volume into tons. First it finds the volume in cubic feet by multiplying length, width and thickness in feet. Then it multiplies by the density — the weight of one cubic foot of compacted asphalt — to get the weight in pounds.
Dividing by 2,000 converts pounds to US tons. The only conversion to watch is thickness: two inches is 2 ÷ 12 = 0.167 feet, which the calculator handles when you select inches.
tons = (length × width × thickness ft × density) ÷ 2,000
Worked Example
For a driveway 40 feet long, 20 feet wide, paved 2 inches thick: the thickness in feet is 2 ÷ 12 = 0.167. The volume is 40 × 20 × 0.167 = 133.3 cubic feet.
Multiply by the density: 133.3 × 145 = 19,333 pounds. Divide by 2,000 and you get about 9.67 tons of asphalt. Order a little over to allow for compaction and edges.
Assumptions and Limitations
- Uses a default density of 145 lb/ft³ for compacted hot-mix asphalt — confirm your mix's density with the supplier
- 'Asphalt' and 'blacktop' refer to the same hot-mix material
- Assumes uniform thickness over a rectangular area; measure irregular areas in sections
- The figure is compacted tonnage; loose delivered weight is similar but compaction reduces volume
When to Use an Asphalt Calculator
Paving contractors and homeowners planning a driveway, parking pad, or private lot use this to estimate the tons of hot-mix asphalt to order. Enter the area and compacted thickness before you call the plant, so you buy enough blacktop in one delivery without overpaying. It is especially useful for weighing a thicker, longer-lasting mat against a thinner budget option, and for checking a contractor's tonnage quote against an independent estimate.
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Open calculator →Frequently Asked Questions
How many tons of asphalt do I need for a driveway?
Multiply length × width × thickness in feet, then by about 145 lb/ft³, then divide by 2,000. A 40 × 20 ft driveway at 2 inches works out to roughly 9.7 tons.
Is blacktop the same as asphalt?
Yes. Blacktop is a common name for hot-mix asphalt — the same material of aggregate bound with asphalt cement. This calculator works for either term.
What density should I use for asphalt?
About 145 pounds per cubic foot is standard for compacted hot-mix asphalt, though it ranges from roughly 140 to 150 depending on the mix. Use your supplier's figure if they provide one.
How thick should asphalt be?
A residential driveway overlay is often 2 inches of compacted asphalt over a solid base; new construction may use 3 inches or more plus an aggregate base. Local conditions and traffic determine the right depth.
Why is asphalt sold by the ton and not the cubic yard?
Because it is a dense, weight-based material delivered by the truckload. Suppliers price and load it by weight, so tonnage is the number you need to order.
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