Asphalt tonnage is square yards × compacted inches × the spread rate ÷ 2,000. At the Asphalt Institute's rule of 110 lb per square yard per inch, one square yard 1 in thick takes 0.055 tons, so 250 SY paved with a 2 in binder lift and a 1 ½ in surface lift needs 27.5 + 20.63 = 48.13 tons, or 52.94 tons with 10% extra: four 15-ton trucks.
How asphalt tonnage is calculated
Paving crews think in square yards and lifts, and the plant bills in tons. The spread rate joins them: it is the weight of compacted mix that covers one square yard one inch deep.
tons per lift = square yards × lift thickness (in) × spread rate (lb/SY·in) ÷ 2,000
Add the lifts for the total, add a margin for edges and low spots, and divide by the truck load to see how many trucks to schedule. The calculator does each lift on its own line so the binder and surface mixes, which usually come from different bins at the plant, get their own tonnage on the material list.
Where 110 lb per SY-inch comes from
A square yard 1 in thick is 9 sq ft × 1/12 ft = 0.75 cu ft. Compacted hot mix weighs roughly 140 to 150 lb/ft³, so 0.75 cu ft weighs 105 to 112 lb. The Asphalt Institute publishes 110 as the typical spread rate, which works out to 146.7 lb/ft³. States set their own: the Illinois DOT uses 112 and the Tennessee DOT 106. Washington's design manual estimates HMA at 2.05 tons per cubic yard, which is about 114 lb per SY-inch, because its mixes run heavy. If your plant or your spec gives a spread rate, type it in; every number on the page follows it.
Worked example: 250 square yards in two lifts
| Lift | Calculation | Tons |
|---|---|---|
| Binder course, 2 in | 250 SY × 2 in × 110 lb ÷ 2,000 | 27.5 |
| Surface course, 1 ½ in | 250 SY × 1.5 in × 110 lb ÷ 2,000 | 20.63 |
| Total, net | 27.5 + 20.63 | 48.13 |
| With 10% extra | 48.13 × 1.1 | 52.94 |
| Trucks at 15 tons | 52.94 ÷ 15, rounded up | 4 (the last with 7.9 tons) |
That is 0.193 tons per SY for the full 3 ½ in, or 5.19 SY per ton. The 250 SY could be a country driveway 12 ft wide and 187 ft 6 in long (2,250 sq ft).
Tons per square yard table
At 110 lb per SY-inch:
| Thickness | Tons per SY | Tons per 1,000 sq ft | Sq ft per ton |
|---|---|---|---|
| 1 in | 0.055 | 6.11 | 164 |
| 1 ½ in | 0.0825 | 9.17 | 109 |
| 2 in | 0.11 | 12.22 | 82 |
| 3 in | 0.165 | 18.33 | 55 |
| 4 in | 0.22 | 24.44 | 41 |
| 6 in | 0.33 | 36.67 | 27 |
The calculator redraws this table for whatever spread rate you enter.
SY to tons without a calculator
Multiply square yards by inches, then by 0.055. For 400 SY at 2 in: 400 × 2 × 0.055 = 44 tons. For square feet, divide by 9 first. To go the other way, tons ÷ (inches × 0.055) gives the square yards a load will cover: one 15-ton truck lays about 136 SY at 2 in.
Lift thickness and multiple lifts
The Asphalt Institute sets a minimum lift of four times the nominal maximum aggregate size for dense-graded mix and three times for finer mixes, so a ½ in surface mix wants at least 1 ½ to 2 in and a ¾ in binder at least 3 in. Thicker pavements are built in several lifts; add a row for each with "Add a lift underneath". Crews set the paver screed about 1.25 times the compacted thickness, but your tonnage always uses the compacted figure.
Truckloads
Fixr puts a paving truck at 13 to 19 tons. Plants load by weight, so the last truck carries only what is left. Order the total rounded to the plant's minimum and have the crew call the final load once they see how far the mix is going.
Next questions
- Measuring a driveway in feet instead? The asphalt calculator takes length × width or a circle and adds the stone base.
- Want the installed price and a concrete or gravel comparison? Open the driveway calculator.
- Base course under the asphalt: the gravel driveway calculator gives tons per layer.
- Hauling off the old pavement first: size the container with the dumpster size calculator.
Every tool for paving is listed on the driveways and paving hub.