How to Calculate Asphalt Tonnage (With a Worked Example)
Published 2026-01-15
To calculate asphalt tonnage, multiply length × width × thickness in feet to get cubic feet, multiply by the 145 lb/ft³ density of hot-mix asphalt, then divide by 2,000. A 50 × 12 ft driveway at 3 inches thick needs about 10.9 tons.
Ordering asphalt by the ton trips up a lot of first-time pavers because the supplier sells by weight, but you measure your driveway by area. Here is the exact conversion, the density that makes it work, and a worked example you can copy.
The formula
tons = length (ft) × width (ft) × (thickness in ÷ 12) × 145 ÷ 2000The 145 is the compacted density of hot-mix asphalt in pounds per cubic foot, a
figure the National Asphalt Pavement Association
uses as a standard for dense-graded mixes. Recycled millings are lighter — about
120 lb/ft³ — so use that number if you are laying millings instead.
Worked example: a 50 × 12 ft driveway
- Area: 50 ft × 12 ft = 600 ft²
- Convert thickness to feet: 3 in ÷ 12 = 0.25 ft
- Cubic feet: 600 × 0.25 = 150 ft³
- Pounds: 150 × 145 = 21,750 lb
- Tons: 21,750 ÷ 2,000 = 10.9 tons
At 13–20 tons per dump truck, that is a single load. Drop your own numbers into the calculator below:
- Cubic feet
- 150 ft³
- Weight
- 21,750 lb
- Truckloads (13–20 t)
- 1
Quick tonnage reference
Tons per 100 ft² of hot-mix asphalt at common thicknesses:
| Thickness | Tons per 100 ft² |
|---|---|
| 2 in | 1.21 |
| 3 in | 1.81 |
| 4 in | 2.42 |
| 6 in | 3.63 |
Multiply the value for your thickness by your area in hundreds of square feet. A 1,000 ft² lot at 3 inches is 10 × 1.81 = 18.1 tons.
Common mistakes
- Measuring compacted vs. loose depth. Asphalt compacts roughly 20–25% during rolling. Quote your compacted thickness — the number above already assumes it.
- Forgetting waste. Add 5–10% for irregular edges, a crowned surface, and the bit that sticks to the truck. The calculator has a waste field for this.
- Mixing up tons and cubic yards. Suppliers may quote either. One cubic yard of hot-mix weighs about 1.96 tons — use the cubic yard calculator if you need to switch units.
FAQ
How many tons of asphalt do I need per square foot? At 2 inches thick, one square foot of hot-mix weighs about 0.012 tons, so 1,000 ft² needs roughly 12 tons.
Does asphalt thickness really matter for tonnage? Yes — tonnage scales directly with thickness. Going from 2 to 3 inches adds 50% more material.
Ready to size your own job? Open the asphalt calculator for tons, truckloads, and cubic yards in one place.