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.