Asphalt is sold by the ton, but driveways and parking lots are measured in square feet. To get from one to the other you need two more numbers: the compacted thickness and the density of the mix. This calculator does the conversion in both directions, shows the arithmetic, and lets you change the density to match your plant's mix instead of hiding it.
Quick answer: tons = square feet × thickness in inches × 0.00604 (at 145 lb/ft³).
So 1,000 sq ft of asphalt at 2 inches is about 12.1 tons, at 3 inches about 18.1 tons, and at 4 inches about 24.2 tons. One ton covers about 83 sq ft at 2 inches.
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How to Convert Square Feet to Tons of Asphalt
Area alone cannot be converted to weight. You first turn the area into a volume, then multiply by how much a cubic foot of compacted asphalt weighs.
- Find the area in square feet. Length × width. A 40 × 20 ft driveway is 800 sq ft.
- Convert the thickness to feet. Divide inches by 12. Three inches is 0.25 ft.
- Get the volume. 800 sq ft × 0.25 ft = 200 cubic feet.
- Multiply by density. 200 ft³ × 145 lb/ft³ = 29,000 lb.
- Divide by 2,000 for US tons. 29,000 ÷ 2,000 = 14.5 tons. Add 5% for waste and you would order about 15.2 tons.
Steps 2 to 5 collapse into one constant. At 145 lb/ft³, one square foot at one inch thick weighs 145 ÷ 12 = 12.08 lb, or 0.00604 tons. That is where the shortcut comes from: tons = sq ft × inches × 0.00604. If your plant quotes a different density, the constant is density ÷ 24,000.
Square Feet to Tons Conversion Chart
Tons of compacted hot mix at 145 lb/ft³, before waste. Most residential driveways are 2 to 3 inches of asphalt; parking lots and heavier-use areas are often 3 to 4 inches, usually placed in two lifts.
| Area (sq ft) | 2 in | 3 in | 4 in |
|---|---|---|---|
| 100 | 1.2 | 1.8 | 2.4 |
| 200 | 2.4 | 3.6 | 4.8 |
| 250 | 3.0 | 4.5 | 6.0 |
| 400 | 4.8 | 7.3 | 9.7 |
| 500 | 6.0 | 9.1 | 12.1 |
| 750 | 9.1 | 13.6 | 18.1 |
| 1,000 | 12.1 | 18.1 | 24.2 |
| 1,500 | 18.1 | 27.2 | 36.3 |
| 2,000 | 24.2 | 36.3 | 48.3 |
| 2,500 | 30.2 | 45.3 | 60.4 |
| 3,000 | 36.3 | 54.4 | 72.5 |
| 4,000 | 48.3 | 72.5 | 96.7 |
| 5,000 | 60.4 | 90.6 | 120.8 |
| 7,500 | 90.6 | 135.9 | 181.3 |
| 10,000 | 120.8 | 181.3 | 241.7 |
To scale: every 1,000 sq ft adds 6.04 tons per inch of thickness.
How Many Square Feet Does a Ton of Asphalt Cover?
This is the same math turned around: divide 1 ton by the tons per square foot. Thickness changes the answer far more than anything else.
| Compacted thickness | Lb per sq ft | Tons per 1,000 sq ft | Sq ft per ton |
|---|---|---|---|
| 1 in | 12.1 | 6.04 | 165.5 |
| 1.5 in | 18.1 | 9.06 | 110.3 |
| 2 in | 24.2 | 12.08 | 82.8 |
| 2.5 in | 30.2 | 15.10 | 66.2 |
| 3 in | 36.3 | 18.13 | 55.2 |
| 4 in | 48.3 | 24.17 | 41.4 |
| 6 in | 72.5 | 36.25 | 27.6 |
A full 20-ton truck therefore covers about 1,655 sq ft at 2 inches, 1,103 sq ft at 3 inches, or 828 sq ft at 4 inches.
Which Density Should You Use?
The Asphalt Institute puts the in-place (compacted) weight of asphalt mixture at 142 to 148 lb/ft³, and its own worked example uses 148. This site defaults to 145, the middle of that range. The difference is small but real: 1,000 sq ft at 2 inches is 11.83 tons at 142 lb/ft³, 12.08 tons at 145, and 12.33 tons at 148. On a driveway that is a rounding error; on a 50,000 sq ft lot at 2 inches, each 3 lb/ft³ of difference moves the order by about 12.5 tons. For bids, ask the plant for the mix design density.
Always enter the compacted thickness. The paver lays a looser, thicker mat that the rollers squeeze down. Asphalt Institute engineers suggest setting the screed at about 1.25 times the finished thickness for dense-graded mixes, so a 2-inch driveway goes down at roughly 2.5 inches. The tonnage is set by the finished 2 inches, not the loose 2.5. If you are working from volumes instead of areas, the cubic yards to tons converter explains compacted and loose density in more detail.
Worked Examples
Example 1: Two-car driveway
A 40 × 20 ft driveway is 800 sq ft. At 3 inches: 800 × 3 × 0.00604 = 14.5 tons (exactly 800 × 0.25 × 145 ÷ 2,000 = 14.5). With 5% waste, order about 15.2 tons, one truckload. The volume is 200 ft³, or 7.4 cubic yards.
Example 2: Small parking lot, 4 inches in two lifts
A 6,000 sq ft lot paved 4 inches thick needs 6,000 × 4 × 0.00604 = 145.0 tons. With 5% waste that is 152.3 tons, or 8 loads at 20 tons. Because the two lifts often use different mixes, you can also run each lift separately in the asphalt tonnage calculator.
Example 3: How far will 20 tons go?
At 2 inches, one ton covers 1 ÷ (2 × 0.0060417) = 82.8 sq ft, so 20 tons covers about 1,655 sq ft. If you hold back 5% for waste and edges, plan on about 1,576 sq ft of finished pavement. Switch the calculator to "Tons → square feet" to run your own numbers.
Tips for an Accurate Order
- Measure odd shapes in pieces. Split the area into rectangles, add the square feet, then convert. The main asphalt calculator handles circles, triangles and multi-section areas.
- Add 5 to 10% waste. Edges, tapers, an uneven base and hand work around drains all eat extra mix. Use the higher end on small or irregular jobs.
- Round up to full trucks. Plants dispatch by the load and some charge for short loads, so check whether rounding up costs less than a second delivery.
- Do not forget the base. New pavement sits on compacted stone. Size it with the gravel base calculator, and price the whole job with the driveway cost calculator.
Related Calculators
Frequently Asked Questions
How many tons of asphalt do I need for 1,000 square feet?
About 12.1 tons at 2 inches thick, 18.1 tons at 3 inches and 24.2 tons at 4 inches, using 145 lb/ft³ compacted density. Add 5 to 10% for waste when you order.
How many square feet does a ton of asphalt cover?
About 83 sq ft at 2 inches, 55 sq ft at 3 inches and 41 sq ft at 4 inches. Divide 165.5 by the thickness in inches for any other depth.
What is the formula for square feet to tons of asphalt?
Tons = square feet × (thickness in inches ÷ 12) × density in lb/ft³ ÷ 2,000. At 145 lb/ft³ this simplifies to square feet × inches × 0.00604.
How many tons of asphalt for a 20 × 20 driveway?
A 20 × 20 ft pad is 400 sq ft. It takes about 4.8 tons at 2 inches or 7.3 tons at 3 inches, before waste.
How much does a square foot of asphalt weigh?
About 12.1 lb per inch of thickness at 145 lb/ft³. A 2-inch layer weighs about 24 lb per square foot and a 3-inch layer about 36 lb.
Should I use compacted or loose thickness?
Compacted. Density figures for hot mix are in-place values, so the finished thickness gives the right tonnage. The loose mat behind the paver is roughly a quarter thicker but weighs the same.
Sources
- Asphalt Institute, Engineering FAQs: Asphalt Pavement Thickness and Mix Design (asphalt mixture weighs about 142 to 148 lb/ft³ in place; worked tonnage example at 148 lb/ft³).
- Danny Gierhart and Jason Wielinski, Asphalt Institute, Five handy rules of thumb for successful asphalt pavement construction, Asphalt Magazine (screed set at about 1.25 times compacted thickness; about 15% roll-down for open- and gap-graded mixes).
- NIST Office of Weights and Measures, Approximate conversions from U.S. customary measures to metric (short ton = 2,000 lb; ton to tonne).
Last updated: October 2026 · How we calculate