Asphalt calculator
Asphalt is quoted and delivered by the ton, but you measure your driveway in feet and inches. This calculator converts area and compacted thickness into tons of hot mix at the standard 145 lb per cubic foot, and sizes the gravel base that goes underneath.
How the asphalt calculator works
Hot-mix asphalt weighs about 145 lb per cubic foot once compacted, or 2 tons per cubic yard. The calculator multiplies your area by the finished thickness to get cubic feet, converts to tons, and adds 5 percent for edges, uneven base, and the bit that cools in the truck. The gravel base is figured separately as a volume with 10 percent for compaction.
Thickness is the compacted, finished depth. Paving crews spread the mix thicker and roll it down, but you order and pay by the finished amount.
Formula
tons = area (sq ft) × thickness (in) ÷ 12 × 145 lb ÷ 2000 × 1.05
Example: a 40 × 12 ft driveway at 3 in is 120 cubic feet of asphalt, which is 8.7 tons at 145 lb per cubic foot, or 9.1 tons with the allowance. The 6 in gravel base underneath is about 9.8 cubic yards, roughly 14.7 tons of crushed stone.
Driveway thickness and cost
| Use | Asphalt | Base |
|---|---|---|
| Overlay on sound existing asphalt | 1.5 to 2 in | None |
| New residential driveway, cars | 3 in | 6 in |
| Driveway with trucks, RV, boat trailer | 4 in | 8 in |
| Commercial lot | 4 to 6 in | 8 to 12 in |
Residential hot mix runs roughly $100 to $200 per ton for material, and installed driveways typically price at $7 to $13 per square foot including base, grading, and rolling. Asphalt is not a DIY material; it arrives at 300 °F and has to be rolled within minutes. Use this calculator to check a contractor's quote, and compare against a slab with the concrete calculator.
Common sizes, already worked out
Common questions
How many tons of asphalt do I need for a driveway?
About 0.9 tons per 100 square feet at 3 in thick, or 1.2 tons at 4 in. A typical two-car driveway of 600 square feet needs 5.5 to 7.5 tons of hot mix.
How much does a ton of asphalt cover?
About 110 square feet at 3 in thick, 165 square feet at 2 in, or 80 square feet at 4 in. One ton is roughly half a cubic yard compacted.
How thick should an asphalt driveway be?
3 in of compacted asphalt over 6 in of compacted gravel for a car driveway. Go to 4 in of asphalt and 8 in of base if heavy trucks or an RV will use it, or if the soil is clay.
How much does a yard of asphalt weigh?
About 3,900 to 4,100 lb compacted, or roughly 2 tons per cubic yard. Loose, uncompacted mix is lighter per yard because of air voids, which is why asphalt is ordered by the ton rather than the yard.