Order 10% too little asphalt and the crew leaves a strip of the driveway unpaved. Order 10% too much and you pay for tons nobody can use, because hot mix can't be stored for next week.
This asphalt tonnage calculator gives you the weight of asphalt a job needs from its area, thickness, and density. It works in feet, yards or metres and returns US tons or metric tonnes. Below the tool you'll find the formulas, worked examples, ready-made charts and the mistakes behind most ordering errors.
How to Use the Asphalt Tonnage Calculator
- 1Enter the length and width of the paved area. If you already know the area, type it in directly.
- 2Enter the thickness of the finished, compacted layer, in whatever unit you measured.
- 3Check the density. The default is 145 lb/ft³ (about 2,320 kg/m³), a common planning value for compacted hot mix asphalt. Replace it with your supplier's number if you have one.
- 4Pick tons or tonnes and read the total weight.
Working on more than one layer? Run the tool once per layer and add the results. Layers often have different thicknesses and sometimes different densities.
The Asphalt Tonnage Formula
The calculation has three steps: find the volume, convert it to weight, then convert the weight to tons or tonnes.
US US units
Tons = Area (ft²) × Thickness (ft) × Density (lb/ft³) ÷ 2,000
SI Metric units
Tonnes = Area (m²) × Thickness (m) × Density (kg/m³) ÷ 1,000
Convert thickness before you multiply. Divide inches by 12 to get feet. Divide millimetres by 1,000 to get metres. Skipping this step gives results that are 12 or 1,000 times too high.
At 145 lb/ft³, a few constants save time on site:
| Quantity | Value |
|---|---|
| 1 inch of asphalt, per ft² | 12.08 lb |
| 1 inch of asphalt, per yd² | 108.75 lb (most estimators round to 110) |
| 2 inches of asphalt, per ft² | 24.2 lb |
| 1 yd³ of compacted asphalt | about 1.96 tons |
| 1 m² at 50 mm (2,350 kg/m³) | 117.5 kg |
Worked Examples
Driveway, 2 inches
A driveway is 12 ft × 50 ft, 2 in thick, at 145 lb/ft³.
Area: 12 × 50 = 600 ft²
Volume: 600 × (2 ÷ 12) = 100 ft³
Weight: 100 × 145 = 14,500 lb
Tons: 14,500 ÷ 2,000 = 7.25 tons
With a 5% allowance, order about 7.61 tons.
Driveway with a turnaround, 3 inches
A strip measures 10 ft × 40 ft. A turnaround pad measures 20 ft × 20 ft.
Area: 400 + 400 = 800 ft²
Volume: 800 × 0.25 = 200 ft³
Weight: 200 × 145 = 29,000 lb
Tons: 14.5 tons, or about 15.2 tons with 5% extra
Parking lot, 3 inches
The lot is 60 ft × 120 ft.
Area: 7,200 ft²
Volume: 7,200 × 0.25 = 1,800 ft³
Weight: 1,800 × 145 = 261,000 lb
Tons: 130.5 tons, or about 137 tons with 5% extra
Ask your supplier about truck capacity before you settle on the final number, since loads come in fixed sizes.
Metric car park, 50 mm
The area is 200 m² and density is 2,350 kg/m³.
Volume: 200 × 0.05 = 10 m³
Weight: 10 × 2,350 = 23,500 kg
Result: 23.5 tonnes, about 25.9 US tons
Square yards
An area is 100 yd² at 3 in thick.
100 × 3 × 110 lb = 33,000 lb
Result: about 16.5 tons
The exact figure at 145 lb/ft³ is 16.3 tons. The shortcut runs slightly high, which is fine for a first estimate.
Two layers
A 10,000 ft² road section gets a 3 in binder course and a 1.5 in surface course.
Binder: 10,000 × 0.25 × 145 ÷ 2,000 = 181.25 tons
Surface: 10,000 × 0.125 × 145 ÷ 2,000 = 90.63 tons
Total: about 271.9 tons
How to Measure Odd-Shaped Areas
Split the surface into simple shapes, find each area, and add them.
Take a circular turnaround with a 30 ft diameter. The radius is 15 ft, so the area is 3.1416 × 225 = 706.9 ft². At 2 in thick, the volume is 117.8 ft³. Multiply by 145 and you get 17,082 lb, or 8.54 tons.
Measure the paved surface only. Leave out curbs, planting beds and any strip that stays unpaved. On a long road, measure the width at several points and use the average.
Asphalt Tonnage Charts
US units (145 lb/ft³)
| Thickness | Tons per 1,000 ft² | Area covered by 1 ton |
|---|---|---|
| 1.5 in | 9.06 | about 110 ft² |
| 2 in | 12.08 | about 83 ft² |
| 2.5 in | 15.10 | about 66 ft² |
| 3 in | 18.13 | about 55 ft² |
| 4 in | 24.17 | about 41 ft² |
| 6 in | 36.25 | about 28 ft² |
Metric units (2,350 kg/m³)
| Thickness | Tonnes per 100 m² | Area covered by 1 tonne |
|---|---|---|
| 30 mm | 7.05 | about 14.2 m² |
| 40 mm | 9.40 | about 10.6 m² |
| 50 mm | 11.75 | about 8.5 m² |
| 75 mm | 17.63 | about 5.7 m² |
| 100 mm | 23.50 | about 4.3 m² |
If your density differs from the table, scale the result. A mix at 140 lb/ft³ weighs about 3.4% less than the 145 lb/ft³ figures shown.
What Changes the Tonnage
Thickness. Weight rises in direct proportion to thickness. Doubling the thickness doubles the tonnage. Small errors add up: a 2-inch layer that averages 2.25 inches uses 12.5% more asphalt than planned. Residential driveways commonly get 2 to 3 inches over a compacted base. Parking lots and roads often need more according to FHWA Pavement Design Guidelines .
Density. Compacted hot mix commonly falls between 140 and 150 lb/ft³ (about 2,240 to 2,400 kg/m³). Specifications from the National Asphalt Pavement Association (NAPA) note that aggregate type and air void target directly shift final compacted density. At 140 lb/ft³ the 7.25-ton driveway from Example 1 drops to 7.0 tons. At 150 lb/ft³ it rises to 7.5 tons.
Base condition. A dipped, rutted or patchy base takes extra material to reach the planned thickness. Crowns and drainage slopes can shift the quantity a little compared with a flat calculation.
Compaction. Asphalt is placed loose and rolled down. Compaction shrinks the volume of the mix, and the weight stays the same. This calculator uses compacted thickness, so the result is the weight needed for the finished layer. Thin layers also have practical limits. Guidelines in the Asphalt Institute MS-2 Mix Design Manual recommend a lift thickness of at least 3 times the nominal maximum aggregate size (NMAS) in the mix.
Edges and transitions. Thickened edges, aprons and tie-ins to existing pavement add area and depth. Include them in your measurements.
How Much Extra to Order
Many contractors add about 5% for edges, uneven spots and small losses. A rough base can push that higher.
Plants sell hot mix by the ton, often with a minimum load. Hot mix also cools on the way to site, so deliveries should match what the crew can lay. For very small repairs, cold patch sold by the bag may suit better than a hot mix load. Your supplier or paving contractor can tell you what is normal for your site.
Tons vs Tonnes
A US ton is 2,000 lb, about 907 kg. A metric tonne is 1,000 kg. One tonne equals 1.1023 US tons, so 100 tonnes is about 110.2 tons, a 10% gap. Confirm which unit your quote uses before you order. A quote in tonnes read as tons leaves you 10% short.
From Tonnage to Bitumen, Tack Coat and Cost
Asphalt mix is aggregate plus bitumen binder. At 5.5% binder, the 12.08 tons per 1,000 ft² at 2 inches contains about 0.66 tons of bitumen.
Use our bitumen calculator to get binder weight, litres, and order quantity for a mix design. The tack coat calculator covers the sprayed layer under each lift. The asphalt driveway cost calculator turns tonnage into a budget. The asphalt millings calculator does the same weight math for recycled material.
Common Mistakes
- ✕
Skipping the thickness conversion. Inches must become feet, and millimetres must become metres.
- ✕
Using binder density instead of mix density. Bitumen is about 1,030 kg/m³ and mix is about 2,350 kg/m³. The wrong choice returns less than half the true weight.
- ✕
Rounding thickness down. Using 2 inches instead of 2.5 inches takes 20% off the order.
- ✕
Counting unpaved areas. Curbs, beds and gaps add tons you never lay.
- ✕
Mixing units mid-formula. Feet for length with inches for thickness gives nonsense unless you convert.
- ✕
Reading tonnes as tons. The 10% difference becomes a shortage on site.
FAQs
Q: How many tons of asphalt do I need per square foot?
At 145 lb/ft³, each inch of thickness needs about 0.006 tons per square foot. Two inches needs about 0.012 tons, roughly 12 tons per 1,000 ft².
Q: How many square feet does 1 ton of asphalt cover?
About 83 ft² at 2 inches, 55 ft² at 3 inches and 41 ft² at 4 inches. Thicker layers cover less area.
Q: How many tons are in a cubic yard of asphalt?
About 1.96 tons of compacted asphalt at 145 lb/ft³.
Q: How do I convert square yards to tons of asphalt?
Multiply the area in square yards by the thickness in inches, then by 110 lb, and divide by 2,000. The square foot formula is more precise.
Q: What density should I use for asphalt?
145 lb/ft³ (about 2,320 kg/m³) is a common planning value. Your supplier's mix design has the exact number.
Q: How thick should an asphalt driveway be?
Many residential driveways use 2 to 3 inches compacted over a prepared base. Heavier traffic needs more, so confirm with your contractor.
Q: Does the result include gravel base?
No. The result covers asphalt only. Base stone is a separate material with its own density.
Q: How accurate is the result?
It is an estimate. Accuracy depends on your measurements, the density you enter and the thickness actually laid.
Conclusion
An asphalt tonnage calculator gives you a planning number in seconds. Measure the paved area carefully, use the compacted thickness, confirm the density with your supplier and add a small allowance. Then check whether the quote is in tons or tonnes before you place the order.
Results are estimates for planning only. Confirm quantities with a qualified contractor or supplier before ordering.