Asphalt Calculator
Estimate the tons of hot-mix asphalt for a driveway or lot from length, width, thickness and mix density.
How it works
volume (ft³) = length × width × (thickness ÷ 12) · weight (lb) = volume × density · tons = weight ÷ 2000
Length and width are in feet and thickness in inches, so thickness is divided by 12 to get feet; multiplying the three gives the compacted volume in cubic feet. Hot-mix asphalt weighs roughly 145 lb per cubic foot, so multiplying volume by density gives pounds, and dividing by 2,000 converts to US tons — the unit paving suppliers quote and bill by. Always round the order up, because a cold joint from running short is far more expensive than a little surplus.
Worked example
A 40 × 20 ft driveway paved 3 in thick: 40 × 20 × (3 ÷ 12) = 200 ft³. At 145 lb/ft³ that is 29,000 lb, or 14.5 tons. Adding 10% for compaction and edge loss, order about 15.95 tons.
Frequently asked questions
How thick should an asphalt driveway be?
A residential driveway is typically 2–3 in of compacted asphalt over 4–8 in of compacted gravel base. Driveways that see heavy vehicles or trucks go to 3–4 in. The base matters as much as the mat — a thin lift over poor base fails fast.
Why is asphalt sold by the ton?
Hot-mix plants batch and weigh by the ton, and trucks are weighed loaded and empty at the scale. Converting your volume to tons with the mix density is how you match a driveway to a delivery ticket and price.
How much extra should I order?
Add about 10%. Asphalt compacts under the roller, edges and transitions eat material, and a partial extra ton is far cheaper than shutting a job down to reorder a small load at a premium.
Related calculators
Estimate for planning. Add a waste margin and confirm with your supplier and local codes.