Asphalt Calculator
Estimate how many tons of asphalt you need for a driveway or parking lot. Enter your measurements below for an instant result.
Tip: hot-mix asphalt is usually 140 to 150 lb/ft³ (145 is standard). Add 5 to 10% for compaction and spillage. Confirm the exact mix density with your local supplier before ordering.
How to calculate asphalt tonnage
Asphalt is ordered by weight, in tons, but you measure your project by area and thickness. To get from one to the other you need the material's density. The formula is:
Tons = Area (ft²) × Thickness (ft) × Density (lb/ft³) ÷ 2000
Thickness is almost always given in inches, so divide it by 12 to convert to feet. The calculator above does all of this for you, then adds a waste allowance for compaction and spillage.
Worked example
A driveway 50 ft long and 20 ft wide, paved 3 inches thick, at a standard density of 145 lb/ft³:
| Area | 50 × 20 = 1,000 ft² |
|---|---|
| Thickness | 3 in ÷ 12 = 0.25 ft |
| Volume | 1,000 × 0.25 = 250 ft³ |
| Weight | 250 × 145 = 36,250 lb |
| Tons | 36,250 ÷ 2000 = 18.13 tons |
Adding a 5% allowance brings the order to about 19 tons.
Typical thickness by project
| Project | Compacted thickness |
|---|---|
| Residential driveway | 2 to 3 in |
| Parking lot (cars) | 3 to 4 in |
| Heavy / commercial use | 4 to 6 in |
Frequently asked questions
How many tons of asphalt do I need for a 2-car driveway?
A typical 2-car driveway of about 600 ft² at 3 inches thick needs roughly 11 tons of asphalt. Use the calculator above with your exact measurements for a precise figure.
What density should I use for asphalt?
Hot-mix asphalt ranges from about 140 to 150 lb/ft³. 145 lb/ft³ is the standard default and is what this calculator uses. Your supplier can give you the exact density of their mix.
Why should I add a waste allowance?
Some material is lost to compaction, uneven sub-base, and spillage during the pour. Adding 5 to 10% ensures you do not come up short mid-project.
How do I convert tons of asphalt to square feet?
It depends on thickness. At 3 inches thick and 145 lb/ft³, one ton of asphalt covers about 55 ft². Thicker layers cover less area per ton.