The formula
Cubic feet = length × width × thickness (ft) Tons = cubic feet × 145 lb ÷ 2,000
Example: a 12 × 50 ft driveway at 2 inches thick is 600 × 2 ÷ 12 = 100 cubic feet. At 145 lb per cubic foot that is 14,500 lb, or 7.25 tons.
Quick answers for common driveways
| Driveway | 2 in thick | 3 in thick |
|---|---|---|
| 10 × 20 ft | 2.4 tons | 3.6 tons |
| 12 × 40 ft | 5.8 tons | 8.7 tons |
| 12 × 50 ft | 7.2 tons | 10.9 tons |
| 20 × 20 ft | 4.8 tons | 7.2 tons |
| 20 × 40 ft | 9.7 tons | 14.5 tons |
| 24 × 50 ft | 14.5 tons | 21.8 tons |
How thick should asphalt be?
Home driveways usually get 2 to 3 inches of compacted asphalt over a well-compacted gravel base of 4 to 8 inches. Heavier traffic needs a thicker base and surface. Contractors often order a little extra for edges and low spots.
Sources and assumptions
The weight uses 145 lb per cubic foot, a typical figure for compacted hot-mix asphalt; your supplier’s mix may differ slightly, so change Weight of asphalt to match.
Questions
How many tons of asphalt do I need for a driveway?
A 12 × 50 ft driveway at 2 inches thick needs about 7.25 tons; at 3 inches it needs about 10.9 tons.
How much area does a ton of asphalt cover?
About 80 square feet at 2 inches thick, or about 55 square feet at 3 inches.
How much does a cubic yard of asphalt weigh?
About 3,900 lb, or nearly 2 tons, at 145 lb per cubic foot.