Skip to content
Calcapedia
Menu
Home & Garden

Asphalt Calculator

Estimate the tons of hot-mix asphalt needed for a driveway or lot from its size, thickness and density.

Level: Grades 6–7

  • Common Core standard 6.G.A.2Find the volume of a right rectangular prism with fractional edge lengths by packing it with unit cubes of the appropriate unit fraction edge lengths, and show that the volume is the same as would be found by multiplying the edge lengths of the prism. Apply the formulas V = l w h and V = b h to find volumes of right rectangular prisms with fractional edge lengths in the context of solving real-world and mathematical problems.
  • Common Core standard 6.RP.A.3.dUse ratio reasoning to convert measurement units; manipulate and transform units appropriately when multiplying or dividing quantities.
Printable worksheet

Asphalt Calculator

Know the answer you need? Pick an input to work backward.

Inputs
Units

Residential driveways are often 2–3 inches over a prepared base.

Typical value: about 145 lb/ft³ for compacted hot-mix asphalt. Ask your supplier for the mix.

A small allowance covers edges, low spots and material left in the truck.

Result

Asphalt to order

9.14 US tons

Order about 9.14 US tons of asphalt (4.67 cubic yards compacted).

Volume
126 ft³
In cubic yards
4.67 yd³
In metric tonnes
8.29 t
Area paved
480 ft²

See the step-by-step solution ↓

Step-by-step solution

  1. Find the area to pave: length × width

    40×12=480 ft²

  2. Find the volume: area × thickness. Dividing inches by 12 turns the thickness into feet

    480×312=120 ft³

  3. Add 5% for edges, low spots and waste

    120×1+0.05=126 ft³

  4. Find the weight: volume × density (the weight of each cubic foot)

    126×145=18,270 lb

  5. Asphalt is sold by weight, so convert to US tons (2,000 lb each)

    18,2702,000=9.135 tons

Test yourself

20 quick questions built from this calculator's formula: work out results, predict what happens when an input changes, and work backward from an answer. Every answer comes with the working.

What this calculator does

Find out how many tons of asphalt to order for a driveway, path or parking area. Hot-mix asphalt is sold by weight, so a paving quote is usually in tons (or tonnes), not cubic yards. To get from a driveway's size to tons, you need three things. They are the area, the thickness of the layer after rolling, and the density (weight per cubic foot) of the rolled mix. This calculator combines them and adds a small allowance for waste.

The density starts at a typical 145 pounds per cubic foot (roughly 2,320 kg/m³), and you can change it. That's a figure often used for rolled hot mix. Real mixes vary with the stone, the binder (the tar-like glue) and how well the layer is rolled. So when your plant or contractor gives you a figure, use theirs.

Where it's used

Why this math matters outside the classroom:

  • Driveway paving. A 40 × 10 ft driveway at 3 in thick holds 100 ft³ of asphalt, which at 145 lb/ft³ is 14,500 lb, or 7.25 tons.
  • Checking quotes. Homeowners compare paving bids by checking that the quoted tonnage matches the area and thickness of the job.
  • Pothole patching. Road crews work out that a 2 × 2 ft pothole 2 in deep needs about 0.67 ft³ of patch material.
  • Parking lots. Property managers estimate resurfacing a 60 × 100 ft lot with a 2 in overlay, which is 1,000 ft³ of mix.
  • Metric jobs. A 5 m × 3 m path laid 5 cm thick needs 0.75 m³, which is about 1.7 tonnes at 2.3 t/m³.

Grade level and standards: Grades 6–7; Common Core State Standards for Mathematics 6.G.A.2, 6.RP.A.3.d. © Copyright 2010. National Governors Association Center for Best Practices and Council of Chief State School Officers. All rights reserved.

How to use it

  1. Choose US units (feet, inches, lb/ft³) or metric units (meters, centimeters, kg/m³).
  2. Enter the length and width of the area to pave, and the compacted (rolled) thickness of the asphalt layer.
  3. Change the density if your supplier gives you one, and set an allowance for waste.
  4. Read the tons to order. You'll also see the volume, and the weight in the other system's tons.

What the inputs mean

Compacted thickness
Use the finished thickness, after rolling. Asphalt is laid loose and then rolled down, so the crew lays it a bit deeper at first. The tonnage depends on the rolled layer.
Asphalt density
145 lb/ft³ is a typical value for rolled hot mix. Porous mixes are lighter, and some mixes with heavy stone are denser. Your supplier can give the figure for their mix.
Extra for waste and uneven base
Covers trimming at the edges, filling low spots in the base and material that can't be used. 5–10% is a common range.

Formula and method

area = length × width
volume = area × thickness   (inches ÷ 12 or cm ÷ 100)
volume to order = volume × (1 + allowance % ÷ 100)
weight = volume to order × density
US tons = pounds ÷ 2,000;  tonnes = kilograms ÷ 1,000

The calculator treats the paved layer as a flat slab. Its volume is the area times the rolled thickness. Its weight is that volume times the density, the weight of each cubic foot (or cubic meter). The allowance % is the extra you add for waste.

Conversions between systems use the exact factors 1 ft³ = 0.028316846592 m³ and 1 lb = 0.45359237 kg. A US (short) ton is 2,000 lb. A metric tonne is 1,000 kg, about 10% heavier.

Worked example

A driveway 40 ft long and 12 ft wide will be paved with a 3 in compacted layer at 145 lb/ft³, with a 5% allowance.

  1. Area: 40 × 12 = 480 ft².
  2. Volume: 480 × (3 ÷ 12) = 120 ft³.
  3. With 5% allowance: 120 × 1.05 = 126 ft³.
  4. Weight: 126 × 145 = 18,270 lb.
  5. Tons: 18,270 ÷ 2,000 = 9.135 US tons.

Result: Order about 9.14 US tons of asphalt, which is 4.67 cubic yards compacted, or about 8.29 metric tonnes.

Understanding the result

Asphalt plants and trucks work in whole or half tons, so round up to the step your supplier uses. Running short in the middle of a job leaves a cold joint, where fresh asphalt meets cooled asphalt. That's a weak spot.

If you're pricing a job, multiply the tons by the price per ton for material. Then add base preparation, hauling and labor separately.

Assumptions and limitations

  • The area is a rectangle, and the rolled layer is the same thickness everywhere.
  • The density you enter is the density of the mix once it's rolled in place.
  • The allowance is one percentage that covers waste and an uneven base.
  • Base layers of gravel or crushed stone aren't included. Work those out separately.
  • For odd shapes, split the area into rectangles and add them together.
  • Density varies between mixes, so the tonnage is an estimate until your supplier confirms it.

Frequently asked questions

How many tons of asphalt are in a cubic yard?

At 145 lb/ft³, a cubic yard (27 ft³) weighs 3,915 lb, or about 1.96 US tons. Most compacted hot mixes fall close to 2 tons per cubic yard.

How thick should an asphalt driveway be?

Residential driveways are commonly 2–3 inches (5–8 cm) of compacted asphalt over a well-compacted stone base. Heavier traffic calls for more. Local soil and climate matter, so take a contractor's advice for your site.

How many square feet does a ton of asphalt cover?

At 145 lb/ft³, a ton (2,000 lb) is about 13.8 ft³. At 2 inches thick that covers roughly 83 ft², and at 3 inches roughly 55 ft².

Why is asphalt sold by weight and not by volume?

Plants weigh each truckload as it leaves, which is accurate and easy to check. The volume shrinks between the loose mix in the truck and the rolled layer on the ground. The weight stays the same.

How this calculator is checked

Method: Slab volume (area × thickness) times a user-editable compacted density; exact US–metric factors. The calculation is covered by automated tests with known reference values and edge cases. Last updated 2026-10-18. Found a problem? Tell us.

Embed this calculator

Put this Asphalt Calculator on your own website or blog for free. Paste this code where you want it to appear: