How to calculate asphalt tonnage
The Pennsylvania Asphalt Pavement Association works out asphalt by the square yard and inch of compacted thickness:
Tons = area (sq yd) × thickness (in) × 110 ÷ 2,000
Square yards = square feet ÷ 9
Example: a 24 × 24 ft driveway, 3 in thick. 24 × 24 = 576 sq ft, ÷ 9 = 64 sq yd. 64 × 3 × 110 = 21,120 lb, ÷ 2,000 = 10.56 tons of asphalt. The 6 in gravel base under it is 576 × 0.5 = 288 cu ft, or 10.67 cu yd; with 15% more for compaction that’s 12.27 cu yd, about 17.2 tons of crushed stone at 1.4 tons per cubic yard.
The thickness is the compacted thickness. The 110 lb figure already allows for compaction, so there’s no need to add more for it. HomeGuide notes that minimum orders are typically 2 tons; for small patches it lists cold-mix asphalt in 50 lb bags.
Coverage per ton
At 110 lb per square yard per inch:
| Compacted thickness | One ton covers |
|---|---|
| 1 1/2 in | 109 sq ft |
| 2 in | 82 sq ft |
| 3 in | 55 sq ft |
| 4 in | 41 sq ft |
| 5 in | 33 sq ft |
| 6 in | 27 sq ft |
Driveway thickness
| Job | Asphalt (compacted) | Base |
|---|---|---|
| Full-depth asphalt | 4 in may do; 5 to 6 in is stronger | none |
| New driveway over gravel | 3 in | 6 to 8 in compacted aggregate |
| Overlay on sound pavement | 1 1/2 to 2 in | existing pavement |
These figures are the Illinois Asphalt Pavement Association’s. It calls full-depth asphalt the best option and describes the gravel base as an option some contractors use. HomeGuide gives 2 to 3 in over a 6 to 8 in base, and 3 to 4 in over 8 to 10 in for heavier vehicles. The Illinois association also stresses good surface drainage, so ask your paver what your site needs.
For a gravel driveway instead, use the gravel calculator; for concrete, the concrete calculator.
For the installed price of an asphalt, concrete or gravel driveway, use the driveway cost calculator.