Asphalt Calculator
Hot-Mix Asphalt Is Priced by the Ton, Not the Square Foot
Paving contractors and asphalt plants quote and invoice by weight, so a driveway measured in length, width, and depth still has to be converted into tons before the number means anything to a supplier. Compacted hot-mix asphalt runs close to 145 lb per cubic foot, a figure consistent enough across the industry to make that conversion reliable.
The Formula
Weight = Volume × 145 lb/cu ft
Length and width are entered in feet, depth in inches. The calculator divides depth by 12 to convert to feet, multiplies through to get cubic feet of asphalt, then multiplies by the standard density of 145 lb per cubic foot for compacted hot-mix asphalt, and finally divides by 2,000 to convert pounds to tons.
Where This Calculation Matters
- Residential driveways — a typical driveway surface course runs 2 to 3 inches deep over a compacted gravel base, and getting the tonnage close avoids a paving crew running short mid-pour, when the mix is already hot and on the clock.
- Parking lots — commercial paving jobs scale the same formula up substantially, where even a small per-square-foot error in depth translates into a large tonnage swing.
- Patch and overlay work — resurfacing an existing surface with a thin overlay uses the same volume-to-weight math at a shallower depth.
Worked Example
A 40 ft × 12 ft driveway (480 sq ft) paved at a 3 in depth:
| Step | Calculation | Result |
|---|---|---|
| Volume | 40 × 12 × (3 ÷ 12) | 120 cu ft |
| Weight | 120 × 145 | 17,400 lb |
| Tons | 17,400 ÷ 2,000 | 8.70 tons |
How to Use This Calculator
- Enter the Length and Width of the area in feet.
- Enter the Depth of the asphalt layer in inches.
- Select Calculate to see the estimated weight in tons.
Related Calculations
Working out the base course first? The Gravel Calculator handles the compacted stone layer beneath the asphalt, and the Construction Cost Calculator can turn the paved area into a rough budget figure.