Asphalt is ordered by weight
Hot mix asphalt is sold by the ton. Compacted density is commonly around 145 pounds per cubic foot, though mixes vary.
Cubic feet = length ft × width ft × (thickness in ÷ 12)
Tons ≈ (cubic feet × 145) ÷ 2000
Example: a 50 × 12 ft driveway at 3 inches compacted.
- 50 × 12 × 0.25 = 150 cubic feet
- (150 × 145) ÷ 2000 = 10.9 tons
Compacted versus laid thickness
Asphalt is spread loose and then rolled. It compacts by roughly 20–25%, so achieving a finished 3 inches means laying closer to 3.75 inches loose.
Quantity calculations should be based on the compacted thickness you want, since that is what the tonnage figure reflects.
Typical thicknesses
| Application | Compacted depth |
|---|
| Residential driveway | 2–3 in surface |
| Driveway with heavy vehicles | 3–4 in |
| Overlay on sound asphalt | 1.5–2 in |
Beneath that sits a compacted aggregate base, typically 6–8 inches for a residential drive and more over poor subgrade. The base does the structural work; the asphalt is a wearing surface.
Temperature and timing
Hot mix arrives at around 275–300°F and must be spread and compacted before it cools below roughly 185°F. That gives a short working window, which is why asphalt crews move fast and why deliveries are staged rather than dumped all at once.
Laying in cold weather shortens the window dramatically. Most contractors avoid paving below about 50°F for this reason — material that cools before compaction never reaches proper density and fails early.