What to measure
How to use the asphalt calculator
Enter the length and width of the area and the compacted thickness (what remains after rolling). For irregular areas, split them into rectangles and add the results.
The formula
- Cubic feet = length × width × thickness (all in feet)
- Tons = cubic feet × 145 ÷ 2,000
Worked example: 12 × 50 ft driveway, 3 in compacted
- 12 × 50 × (3 ÷ 12) = 150 cu ft (5.56 cubic yards)
- 150 × 145 = 21,750 lb = 10.88 tons
Typical thickness
| Use | Compacted asphalt | Gravel base |
|---|---|---|
| Walkway, path | 2 in | 4 in |
| Residential driveway | 2–3 in | 6–8 in |
| Heavy vehicles | 3–4 in | 8–12 in |
Size the base with the gravel calculator.
Tons by driveway size
Compacted thickness, 145 lb per cubic foot, no extra.
| Area | 2 in | 3 in | 4 in |
|---|---|---|---|
| 10 × 20 ft | 2.42 tons | 3.63 tons | 4.83 tons |
| 12 × 30 ft | 4.35 tons | 6.53 tons | 8.7 tons |
| 12 × 50 ft | 7.25 tons | 10.88 tons | 14.5 tons |
| 20 × 20 ft | 4.83 tons | 7.25 tons | 9.67 tons |
| 20 × 40 ft | 9.67 tons | 14.5 tons | 19.33 tons |
| 24 × 60 ft | 17.4 tons | 26.1 tons | 34.8 tons |
Common mistakes
- Entering the loose thickness. Asphalt is rolled down after it is spread. Enter the thickness you want after compaction.
- Ordering in cubic yards. Plants sell hot mix by the ton. Use the tonnage, not the cubic yards.
- Skipping the base. The thicknesses above assume a compacted gravel base under the asphalt. Size it with the gravel calculator too.
- Ordering the exact tonnage. Uneven base and edges use more. Add the extra your paving crew recommends and round up.
Frequently asked questions
How much does asphalt weigh?
Compacted hot-mix asphalt weighs about 145 lb per cubic foot, roughly 1.96 tons per cubic yard. Most plants and state DOTs use 145–150 lb for estimating.
How thick should an asphalt driveway be?
2–3 inches of compacted asphalt over a well-compacted gravel base of 6–8 inches is typical for cars. Driveways carrying trucks or RVs use 3–4 inches.
How many tons of asphalt do I need for a 12 x 50 driveway?
At 3 inches compacted, 12 × 50 × 0.25 = 150 cubic feet × 145 lb = 21,750 lb, or about 10.9 tons.
Do I need extra for waste?
Plants load by the ton, and paving crews usually add 5–10% for uneven base and edges. Enter the base area and round your order up.
How much asphalt do I need for 1,000 square feet?
About 12.08 tons at 2 inches compacted, using 145 lb per cubic foot.
How many tons of asphalt for a 20 x 40 driveway?
9.67 tons at 2 inches compacted, 14.5 tons at 3 inches and 19.33 tons at 4 inches.
How much asphalt to patch a small area?
A 4 × 6 ft patch 2 inches thick is 4 cubic feet, about 580 lb or 0.29 tons. Enter the patch size and compacted depth the same way as a driveway.
How many square feet does a ton of asphalt cover?
At 145 lb per cubic foot, about 83 sq ft at 2 inches compacted, 55 sq ft at 3 inches and 41 sq ft at 4 inches.
Sources
Formulas and defaults last reviewed October 30, 2026. How we check our math.