Asphalt Calculator

In this guide

• What is an asphalt calculator?
• How to use this asphalt calculator
• Asphalt calculation formula
• Asphalt calculation examples
• Asphalt tonnage chart
• How far does a ton of asphalt go?
• How thick should asphalt be?
• Understanding asphalt density
• Irregular shapes
• Hot mix vs. cold patch
• Ordering asphalt
• Asphalt paving cost
• Asphalt vs. concrete
• Weather and care for new asphalt
• Common asphalt estimating mistakes
• Unit conversions
• Accuracy and limitations
• Frequently asked questions

What is an asphalt calculator?

An asphalt calculator estimates how many tons of asphalt a paving job needs. You enter the length, width and thickness of the area, and the asphalt calculator turns those measurements into area, volume, weight and, if you add a price, material cost. It replaces a handful of manual conversions with one quick check, whether you are pricing a driveway, ordering for a parking lot or comparing contractor quotes.

Asphalt is sold by weight, not by volume, which is what makes the estimate tricky. You measure in feet and inches, but the plant sells by the ton, so the calculation has to bring in the density of the mix. A good estimate before you call your supplier or contractor helps you understand the quote, spot a number that looks off and plan your budget.

Homeowners use an asphalt calculator to budget a new or resurfaced driveway. Paving contractors and estimators use it to bid jobs and check supplier quotes. Property managers use it for parking lot repaving and repairs, and it works just as well for walkways, bike paths, courts and large patches.

How to use this asphalt calculator

1. Choose US or metric units. US units are selected by default.
2. Enter the length and width of the paved area. For an irregular shape, split it into simple shapes, calculate each one and add the totals.
3. Enter the compacted thickness you plan to pave. Driveways are commonly 2 to 3 inches, while heavier-use areas often need more.
4. Check the density. The default is 145 lb/ft³, which you can replace with the figure from your supplier or project specifications.
5. Pick an optional waste allowance and, if you like, enter your price per ton to see an estimated material cost.
6. Press Calculate Asphalt, then copy or print the summary to share with a supplier or client.

Asphalt calculation formula

The math behind the calculator is simple, and every step is shown in the results:

• Area (sq ft) = length (ft) × width (ft)
• Volume (cu ft) = area × thickness (in) ÷ 12
• Weight (lb) = volume × density (lb/ft³)
• US short tons = weight ÷ 2,000

For example, a 100 ft by 20 ft area paved 4 inches thick at 145 lb/ft³ has an area of 2,000 sq ft and a volume of 666.67 cu ft. That weighs about 96,667 lb, or 48.33 US short tons. The metric version works the same way, using meters, centimeters divided by 100, kilograms per cubic meter and a final division by 1,000 for tonnes.

A handy shortcut at 145 lb/ft³: tons ≈ square feet × thickness in inches ÷ 165.5. The calculator uses the exact figures, so you don’t have to remember it, but it is useful for a quick check.

Asphalt calculation examples

Example 1: a one-car driveway. A driveway 12 feet wide and 24 feet long, paved 2 inches thick, covers 288 square feet and needs about 3.48 tons. With a 10 percent allowance, that becomes about 3.83 tons.

Example 2: a two-car driveway. A driveway 20 feet wide and 24 feet long, paved 3 inches thick, covers 480 square feet and needs about 8.70 tons, or about 9.57 tons with 10 percent extra.

Example 3: a small parking lot. A lot 40 feet by 60 feet, paved 3 inches thick, covers 2,400 square feet and needs about 43.50 tons.

Example 4: a pothole patch. A patch 4 feet by 4 feet and 3 inches deep holds 4 cubic feet, which is about 580 pounds, or 0.29 tons. Small repairs like this are usually done with cold patch bags or a small hot mix order.

Example 5: a long lane. A private road 500 feet long and 12 feet wide, paved 3 inches thick, covers 6,000 square feet and needs about 108.75 tons.

Example 6: a circular turnaround. A circle with a 20-foot radius covers about 1,257 square feet (π × 20²). Paved 3 inches thick, it needs about 22.78 tons.

Example 7: a metric job. A path 20 meters long and 5 meters wide, paved 5 centimeters thick at 2,323 kg/m³, has a volume of 5 cubic meters and needs about 11.6 metric tonnes.

Asphalt tonnage chart

These are approximate US short tons at 145 lb/ft³, with no waste allowance added:

How far does a ton of asphalt go?

The area a ton covers depends on thickness. The thicker the layer, the less ground a ton covers. At 145 lb/ft³:

Because tons per 1,000 square feet scales directly with thickness, an extra half inch of asphalt adds about 3 tons for every 1,000 square feet. That is why a small change in thickness has a large effect on the total.

How thick should asphalt be?

These are common compacted thicknesses. Your local requirements, soil, drainage and traffic loads can call for more, so confirm with your contractor.

• Residential driveways: commonly 2 to 3 inches over a properly prepared base.
• Overlays on existing pavement: often 1.5 to 2 inches, if the pavement underneath is sound.
• Commercial parking lots: commonly 3 to 4 inches, depending on traffic.
• Heavy truck areas and roads: thicker, often built in more than one layer with an engineered base.

Thickness in the calculator should be the finished, compacted depth. Hot mix is laid thicker than the final depth and then compacted by rolling, and your contractor handles that, so you should order by the final thickness. A thick layer on a weak base will still fail early, which is why base preparation matters as much as the asphalt itself.

Understanding asphalt density

Density is the weight of asphalt per cubic foot, and it depends on the mix design, the aggregate and how well the pavement is compacted. A figure near 145 lb/ft³ is a common planning number, which works out to roughly 110 pounds per square yard for every inch of thickness and to about two tons per cubic yard. The metric default of 2,323 kg/m³ is the same density expressed in kilograms.

Your supplier’s delivery tickets are the most reliable source, so enter their number whenever you have it. If your mix is a little denser, the calculator will show a little more tonnage for the same area.

Irregular shapes

Few driveways and lots are perfect rectangles. To handle that, split the area into simple shapes, find the area of each, and add them:

• Rectangle: length × width
• Triangle: ½ × base × height
• Circle: π × radius²
• Trapezoid: ½ × (side A + side B) × height

Add the areas together, then divide by a convenient width to get an equivalent length. For example, 1,200 square feet over a 20-foot width is a 60-foot length. Enter those two numbers and your thickness in the calculator. For a rough check, round up for curves and wide aprons where the driveway meets the street, which often use more material than they appear to.

Hot mix vs. cold patch

Hot mix asphalt is produced at a plant and delivered hot, usually by dump truck. It has to be placed and compacted quickly while it is still hot, and it is the standard choice for driveways, lots and roads. Cold patch is a bagged or bulk material that can be used at air temperature, typically for temporary or small repairs such as potholes, especially in cold weather. It has a different density and a different yield, so for cold patch use the yield printed on the bag instead of the default density in this calculator.

Ordering asphalt

Plants sell hot mix by the ton and deliver it by truck. Common dump trucks carry roughly 10 to 20 tons depending on the type, and plants often have minimum order sizes and may charge extra for small or partial loads. A few practical points:

• Call ahead for the plant’s price, the mix type and minimum load.
• Ask the contractor who arranges the order, since many handle it as part of the job.
• Keep the weight tickets from each load, which show what was actually delivered.
• Aim to order close to the estimate, because leftover hot mix can’t be stored.
• Have the base ready before the trucks arrive, since the mix cools while it waits.

Asphalt paving cost

To estimate the material cost, multiply the tons by the plant’s price per ton. As an illustration only, a two-car driveway needing 8.70 tons at $100 per ton costs $870 in material, or about $957 with a 10 percent allowance. To find the material cost per square foot, multiply your price per ton by the thickness in inches and divide by 165.5. At $100 per ton and 2 inches, that is about $1.21 per square foot.

The asphalt is only part of a paving job. A full quote also includes:

• Excavation, grading and a compacted gravel base
• Delivery, fuel and any short-load fees
• Equipment such as pavers and rollers, and the crew that runs them
• Tack coat, edging and drainage work
• Removal of old pavement, if you are not paving over it
• Permits, sealcoating and taxes

Because labor and base work are a large share of the total, an estimate from this calculator is best used to understand a contractor’s quote, not to replace one.

Asphalt vs. concrete

If you are deciding between the two for a driveway or lot, here is how they generally compare. Conditions in your area matter, so treat these as general tendencies.

To compare costs for the same area, estimate concrete with the Concrete Calculator, which returns cubic yards and an optional slab cost.

Weather and care for new asphalt

Asphalt is best placed on a dry day when the air and ground are warm enough, since cold ground makes the mix cool before it can be compacted. Many contractors avoid paving in rain or in freezing temperatures, and they prefer mild to warm weather.

After paving, many contractors suggest keeping cars off for about two to three days, longer in hot weather, and avoiding turning the steering wheel while stopped for the first few weeks, which can scuff the surface. Heavy items like trailers and dumpsters are best kept off new pavement for longer. Sealcoating is often recommended after the asphalt has had time to cure, commonly several months to a year, and again every few years. Follow the guidance from your paving contractor.

Common asphalt estimating mistakes

• Using loose thickness instead of compacted thickness. Order by the finished depth.
• Mixing up inches and feet. Thickness is in inches, but length and width are in feet.
• Mixing up tons and tonnes. A US short ton is 2,000 lb; a metric tonne is about 2,205 lb.
• Ignoring curves and aprons. They add area that simple rectangles miss.
• Forgetting the base. Gravel and grading are separate materials and costs.
• Ordering the exact calculated amount. Allow a little for edges and an uneven base.
• Assuming every mix has the same density. Use your supplier’s number if you have it.

Unit conversions

These are the conversions used behind the scenes:

• 1 US short ton = 2,000 lb ≈ 0.9072 metric tonnes
• 1 metric tonne = 1,000 kg ≈ 1.1023 US short tons
• 1 cubic foot ≈ 0.0283 cubic meters
• 145 lb/ft³ ≈ 2,323 kg/m³
• 1 inch = 2.54 centimeters, 1 foot = 0.3048 meters

Accuracy and limitations

This asphalt calculator gives a planning estimate, not a bid or an engineering specification. It does not include base stone, tack coat, labor, equipment, trucking or taxes. Before ordering, confirm the quantity, density and thickness with your asphalt supplier or paving contractor, and follow the requirements of your local jurisdiction.