A 40 by 12 ft driveway paved 3 in thick takes 8.7 tons of hot mix asphalt, or 9.57 tons with 10% extra, which is one truckload. Hot mix is sold by weight, so the job is always area × compacted thickness × density: 480 sq ft × 0.25 ft × 145 lb/ft³ = 17,400 lb, and 17,400 ÷ 2,000 = 8.7 tons.
How the asphalt calculator works
Asphalt plants load and bill by the ton, but you measure a driveway in feet. The calculator bridges the two in three steps:
tons = area (sq ft) × thickness (in) ÷ 12 × density (lb/ft³) ÷ 2,000
- Area. Length × width for a rectangle, π × diameter² ÷ 4 for a round pad or turnaround, or type the square feet or square yards straight from a bid.
- Volume. Area × the compacted thickness in feet. Use the thickness after rolling, not the loose depth behind the paver: the Asphalt Institute tells crews to set the screed about 1.25 times the finished thickness, because the roller squeezes the mat down by that much.
- Weight. Volume × density, then ÷ 2,000 for US tons (or ÷ 1,000 for metric tonnes).
The default density is 145 lb/ft³ (2,323 kg/m³) for dense-graded hot mix. It is an input, because mixes differ: a mix with heavy trap rock weighs more than one with limestone. If your plant gives you a number, type it in.
Worked example: a 40 × 12 ft driveway at 3 in
| Step | Numbers | Result |
|---|---|---|
| Area | 40 ft × 12 ft | 480 sq ft (53.3 sq yd) |
| Volume | 480 sq ft × 0.25 ft | 120 cu ft (4.44 cu yd) |
| Weight | 120 cu ft × 145 lb/ft³ | 17,400 lb = 8.7 tons |
| Order | 8.7 tons × 1.10 | 9.57 tons |
| Cost | 9.57 tons × $125 | about $1,196 |
The same answer comes out the square-yard way: 53.33 SY × 3 in × 108.75 lb per SY-inch ÷ 2,000 = 8.7 tons. A 6 in crushed stone base under it adds 16.4 tons of stone (18.1 tons with the same 10% extra) at 1.85 tons per compacted cubic yard, the figure WSDOT uses for crushed surfacing.
Square feet to tons
At 145 lb/ft³ every 1,000 sq ft of asphalt 1 in thick weighs 6.04 tons. Multiply by your thickness:
| Compacted thickness | Tons per 1,000 sq ft | Sq ft per ton |
|---|---|---|
| 1 ½ in (overlay) | 9.06 | 110 |
| 2 in | 12.08 | 83 |
| 3 in | 18.13 | 55 |
| 4 in | 24.17 | 41 |
| 6 in | 36.25 | 28 |
Square yards to tons
Road bids and DOT plans measure in square yards (SY). One SY at 1 in thick is 0.75 cu ft, so at 145 lb/ft³ it weighs 108.75 lb. The Asphalt Institute's field rule is 110 lb per SY-inch, which matches a slightly heavier 146.7 lb/ft³; the Illinois DOT uses 112 and the Tennessee DOT 106. The asphalt tonnage calculator works directly in square yards and lifts with that spread rate.
How thick should a driveway be?
The Illinois Asphalt Pavement Association recommends 3 in of asphalt placed as two lifts of about 1 ½ in over 6 to 8 in of compacted aggregate base, and notes that 4 in can be adequate while 5 or 6 in of full-depth asphalt is stronger. It rates 1 in of asphalt as worth 3 in of stone base. An overlay on sound old pavement needs 1 ½ to 2 in. Each lift should be at least four times the nominal maximum stone size of a dense-graded mix (Asphalt Institute), so a mix with ½ in stone wants lifts of 2 in or more. The calculator splits anything from 2 ½ in up into a binder course and a 1 ½ in surface course in the drawing so you see how it goes down.
Price per ton and truckloads
Fixr's 2022 cost guide lists hot mix at $100 to $150 a ton and says a paving truck carries 13 to 19 tons. The default of $125 and 15 tons are midpoints; call your nearest plant for today's price, which moves with the price of liquid asphalt. For the whole installed price with base and labor, see the driveway calculator.
Cold patch bags for pothole repairs
Switch to Repair for potholes. Cold patch is sold in 50 lb bags, and Black Jack's data sheet rates one bag at about 5.6 sq ft at 1 in thick (Latex-ite rates its 55 lb pail at 5.5 sq ft). A 2 × 2 ft hole 2 in deep is 8 sq ft·in, so 8 ÷ 5.6 = 1.43 and you buy 2 bags. Square up the edges, fill in layers of 1 to 2 in and tamp each one, and mound the last layer slightly so traffic packs it flush.
Next steps
- Two surfaces to compare? Price asphalt against stone in the gravel driveway calculator.
- Paving on a hill: check the driveway slope calculator before you set grades.
- Wait about six months, then work out pails with the driveway sealer calculator.
- Pouring the apron or a walk in concrete instead? Use the concrete calculator.
More tools for the whole job are on the driveways and paving hub.