How to use the asphalt calculator
- Select Asphalt (tonnage) for new paving or Sealcoat (gallons) for maintenance.
- Enter the length and width of the area in feet.
- For asphalt, set the compacted thickness in inches (typically 2 to 3 inches for driveways).
- Adjust the price per ton or sealcoat coverage rate to match your local supplier.
- Read the calculated tons, volume, cost or gallons directly below the inputs.
How the asphalt tonnage formula works
This asphalt calculator uses the standard industry formula based on a compacted hot mix density of 145 pounds per cubic foot. The steps are straightforward:
- Multiply length by width to get the area in square feet.
- Divide the thickness in inches by 12 to convert it to feet.
- Multiply area by thickness in feet to get the volume in cubic feet.
- Multiply the volume by 145 lb/ft3 to get the weight in pounds.
- Divide by 2,000 to convert pounds to US short tons.
For example, a 100-foot long by 10-foot wide driveway paved at 2 inches thick: 100 x 10 = 1,000 sq ft. Thickness is 2 / 12 = 0.1667 ft. Volume is 1,000 x 0.1667 = 166.67 cu ft. Weight is 166.67 x 145 = 24,167 lbs. Tons: 24,167 / 2,000 = 12.08 tons. You can verify this yourself by entering those dimensions into the asphalt calculator above.
Common asphalt driveway thicknesses
Choosing the right depth is critical when using an asphalt driveway calculator. Too thin and the surface cracks under vehicle loads; too thick and you overpay for material. Here are typical compacted thicknesses for residential and light commercial work:
| Application | Compacted thickness | Notes |
|---|---|---|
| Residential driveway | 2 to 3 inches | Adequate for passenger cars and light trucks |
| Parking lot (cars) | 3 to 4 inches | Often laid over a compacted aggregate base |
| Heavy truck areas | 4 to 6 inches | Requires engineered base layers |
| Overlay / resurfacing | 1.5 to 2 inches | Applied over existing sound pavement |
Always confirm the required depth with your paving contractor, as local soil conditions and climate affect the specification.
Using the sealcoat calculator
Switch the tool to sealcoat mode to act as a driveway sealer calculator. Sealcoating protects asphalt from UV damage, water intrusion and oil spills. The default coverage rate is 78 square feet per gallon, which is a common rule of thumb for coal tar or asphalt emulsion sealers applied by squeegee or spray.
To find the gallons needed, divide the total area by the coverage rate. A 40 by 20 foot driveway is 800 square feet. At 78 sq ft/gal, you need 800 / 78 = 10.26 gallons. Always round up to the next full pail or drum, because running short mid-job leaves visible lap marks.
Note that actual coverage varies with surface texture, temperature and application method. Rough, oxidized asphalt absorbs more sealer than a smooth, recently paved surface. Check the manufacturer's data sheet for the specific product you buy and adjust the coverage field accordingly.
Ordering tips and waste factor
The asphalt tonnage calculator gives you the theoretical compacted weight. In practice, order 5 to 10 percent extra to account for spillage, uneven subgrade and compaction variations. If the math says 12 tons, request 12.6 to 13.2 tons from the plant.
Hot mix asphalt cools quickly. For small projects, schedule delivery so the truck arrives when your crew is ready to spread and roll. Material that drops below 175 degrees Fahrenheit becomes difficult to compact properly, leading to premature raveling.
If you are comparing materials for a base layer, you might also need a gravel calculator for the aggregate sub-base or a stone calculator for crushed rock edging. Measure your total project footprint first with a square footage calculator if the shape is irregular.
Density assumptions and limitations
This tool assumes a compacted density of 145 lb/ft3, which is standard for dense-graded hot mix asphalt (HMA) containing typical aggregates. Open-graded friction courses or mixes with lightweight aggregate will have a lower density, while polymer-modified or stone-matrix mixes may be slightly heavier.
The calculation returns the mass of the finished, compacted mat. Loose asphalt straight out of the truck weighs less per cubic foot because it contains air voids that are removed during rolling. Do not use the loose density figure when estimating how much material to order; always calculate based on the compacted state.
For projects involving other bulk materials, such as pouring a concrete apron at the garage entrance, use a dedicated concrete calculator since concrete has a different density and is measured by volume rather than weight.
Worked examples
| Example | Input | Result |
|---|---|---|
| Standard two-car driveway | Mode: asphalt; Length (ft): 40; Width (ft): 20; Thickness (inches): 2; Price per ton ($): 110 | Area: 800 sq ft; Volume: 133.33 cu ft; Tons of asphalt: 9.667; Estimated cost: $1,063.33 |
| Small parking lot | Mode: asphalt; Length (ft): 100; Width (ft): 60; Thickness (inches): 3; Price per ton ($): 95 | Area: 6,000 sq ft; Volume: 1,500 cu ft; Tons of asphalt: 108.75; Estimated cost: $10,331.25 |
| Driveway sealcoating | Mode: sealcoat; Length (ft): 40; Width (ft): 20; Sealcoat coverage (sq ft/gal): 78 | Area: 800 sq ft; Gallons of sealcoat: 10.256; Coverage rate used: 78 sq ft/gal |
| Parking lot sealcoating | Mode: sealcoat; Length (ft): 100; Width (ft): 60; Sealcoat coverage (sq ft/gal): 70 | Area: 6,000 sq ft; Gallons of sealcoat: 85.714; Coverage rate used: 70 sq ft/gal |
FAQ
How many tons of asphalt do I need for a 20x40 foot driveway?
At 2 inches thick, a 20 by 40 foot driveway requires about 5.8 tons of compacted hot mix. Add 5 to 10 percent for waste, bringing the order to roughly 6.1 to 6.4 tons.
What does a ton of asphalt cover?
One ton of asphalt covers approximately 80 square feet at 2 inches thick, or about 160 square feet at 1 inch thick, assuming a compacted density of 145 lb/ft3.
How much does asphalt cost per ton?
Hot mix asphalt typically costs between $80 and $150 per ton delivered, depending on your region, the mix design and current oil prices. Installed costs including labor and equipment are higher.
How many gallons of sealer do I need for my driveway?
Divide your driveway area in square feet by the coverage rate on the sealer bucket. Using the standard 78 sq ft/gal rule, an 800 sq ft driveway needs about 10.3 gallons.
Should I measure asphalt in tons or cubic yards?
Asphalt is sold by the ton, not by the cubic yard. This asphalt tonnage calculator converts your dimensions directly into weight so you can place an accurate order with the plant.
Does this tool work for patching potholes?
Yes. Enter the approximate length, width and depth of the pothole to estimate the pounds or tons of cold patch or hot mix required. For very small patches, convert the result to pounds by multiplying tons by 2,000.
Is my data sent to a server?
No. The calculator runs entirely in your browser. Dimensions and prices are never transmitted anywhere.