Asphalt Tonnage Calculator: How to Figure Tons of Asphalt

Asphalt tonnage calculator

Enter the patch or section size and the compacted depth. Results update as you type.

Measure by Length × width Total square feet Length (ft) Width (ft) Total square feet Compacted depth (in) Waste (%) Density 159 rule (≈151 lb/ft³) 110 lb per SY-inch 115 lb per SY-inch Custom (lb/ft³) Custom density (lb/ft³)

–square feet

–square yards

–cubic yards (compacted)

–tons, incl. waste

–tons per 100 SF (before waste)

Estimates only. Check the unit weight of your actual mix with your supplier before ordering.

How to calculate tons of asphalt

Asphalt is sold by the ton, but you measure it on the ground in feet and inches. The formula for asphalt tons bridges the two:

Tons = (Length ft × Width ft) ÷ 159 × Depth in

Step by step:

1. Get square feet. Length × width in feet. Break odd shapes into rectangles and add them up.
2. Divide by 159. That gives tons per inch of compacted depth.
3. Multiply by the compacted depth in inches. Use the finished thickness, not the loose lay depth.
4. Add waste. Multiply by 1.05 for 5%, 1.10 for 10%, and so on.

That's the whole asphalt calculator, square feet to tons, in four steps. It is the same formula the Jobsite Reel app uses for asphalt items, and the 159 divisor is editable in the app's settings if your shop uses a different number.

Why the divisor is 159

The 159 isn't magic. It falls out of a density assumption:

• One square foot of asphalt 1 inch thick is 1 × 1 × 1/12 = 1/12 of a cubic foot.
• At about 151 lb per cubic foot, that slab weighs 151 ÷ 12 ≈ 12.6 lb.
• One ton is 2,000 lb, so it takes 2,000 ÷ 12.6 ≈ 159 square-foot-inches to make a ton.

Run it backwards and the exact density behind the rule is 2,000 × 12 ÷ 159 = 150.9 lb/ft³. A square yard is 9 square feet, so a square yard 1 inch thick is 0.75 ft³, and 0.75 × 150.9 = 113.2 lb per square-yard-inch. That sits between the two rules of thumb you'll hear on most paving crews: 110 and 115 lb per SY-inch.

Asphalt weight per square yard inch: 110 vs 115 vs 159

Estimators quote asphalt weight a few different ways. They all describe the same thing: how heavy the compacted mat is. Here's how they line up:

The 110 lb figure shows up in agency references; for example, Michigan DOT's construction manual lists 110 lb/syd as the application rate for a 1-inch mat in its HMA application-rate conversion table. Treat all three as planning numbers. Actual unit weight depends on the aggregate, the mix design and how well it's compacted. The AAPTP Asphalt Paving Handbook describes spread rate as based on the lab unit weight of the mix, in pounds per square yard per inch of compacted thickness. When your plant or the project spec gives you that number, use it. The calculator's custom density option takes lb/ft³; to convert from lb/SY-in, divide by 0.75.

Cubic yards to tons of asphalt

If you've already figured volume in cubic yards, maybe from a takeoff or a sitework spreadsheet, convert it with the density:

Tons = CY × 27 × density (lb/ft³) ÷ 2,000

A cubic yard is 27 cubic feet. At the 159 rule's 150.9 lb/ft³, one cubic yard weighs 27 × 150.9 ≈ 4,075 lb, or 2.04 tons. That's the assumption to state when someone asks for a single number. The honest answer is a range:

How many tons in a cubic yard of asphalt?

Roughly 2 tons of compacted hot-mix, give or take about 5% depending on the mix. If you're quoting a big job, a 5% swing in density is a 5% swing in tonnage, so get the mix's unit weight from your supplier rather than relying on any single published figure, including ours.

Loose vs. compacted asphalt

Asphalt weight per cubic yard depends on whether you mean loose mix in the truck bed or the finished, rolled mat. Loose mix takes up more room, so a cubic yard of it weighs less than a cubic yard of compacted pavement. The tonnage doesn't change when it's rolled; only the volume does. That's why every formula on this page uses compacted depth. The paver lays the mat thicker so it can roll down to finished grade; the AAPTP handbook puts rolldown for a typical dense-graded mix at roughly 25%. If you measure the loose mat and plug it into the formula, you'll over-order.

Worked examples

Example 1: 12 × 8 ft pothole patch at 3 inches

• Square feet: 12 × 8 = 96 SF (10.7 SY)
• Tons: 96 ÷ 159 × 3 = 1.81 tons
• With 5% waste: 1.81 × 1.05 = 1.90 tons
• Volume check: 96 × 3 ÷ 12 ÷ 27 = 0.89 CY × 2.04 = 1.81 tons ✓

Small patches are where waste matters most. A sawcut that wanders, a soft spot you dig out deeper, or extra for raking the edges can easily eat more than 5% on a 2-ton patch. Measure the depth at a few points after the cut is cleaned out.

Example 2: 60 × 20 ft parking lot section at 2 inches

• Square feet: 60 × 20 = 1,200 SF (133.3 SY)
• Tons: 1,200 ÷ 159 × 2 = 15.09 tons
• With 5% waste: 15.09 × 1.05 = 15.85 tons
• Volume: 1,200 × 2 ÷ 12 ÷ 27 = 7.41 CY compacted

Here's how the same section comes out under each density rule, before waste:

The spread is about two-thirds of a ton on a 15-ton section. On a single section that's noise; across a whole lot it can be a truckload, which is another reason to pin down your mix's real unit weight.

Example 3: L-shaped driveway apron at 2.5 inches

Split the L into two rectangles: 40 × 10 ft and 15 × 12 ft.

• Square feet: 400 + 180 = 580 SF (64.4 SY)
• Tons: 580 ÷ 159 × 2.5 = 9.12 tons
• With 5% waste: 9.12 × 1.05 = 9.58 tons

For irregular shapes, switch the calculator to "Total square feet" and enter the summed area directly.

Example 4: converting cubic yards to tons

A takeoff shows 7.41 CY of compacted surface course. At the 159 rule's density: 7.41 × 2.04 ≈ 15.1 tons, which matches Example 2, as it should. At an assumed 145 lb/ft³ it would be 7.41 × 1.96 ≈ 14.5 tons.

Tons of asphalt per 100 square feet by depth

A quick field reference using SF ÷ 159 × depth, before waste. Multiply by your square footage ÷ 100.

How many tons of asphalt do I need? Getting the order right

The math is easy. The measuring is where estimates go wrong. A few habits that keep the number honest:

• Measure after the cut, not before. Patch limits grow once the saw finds where the failure really ends. Re-measure the open hole if you can.
• Check depth in several spots. Base is rarely flat. Average three or four depth readings on any patch bigger than a parking space.
• Separate layers. If you're placing a base course and a surface course, figure each layer's tons on its own depth, because they may be different mixes with different unit weights.
• Pick a waste allowance and stick to it. Many crews add a few percent for handwork, edges and an uneven base. The calculator defaults to 5%; raise it for lots of small patches.
• Write it down where you measured it. Dimensions scribbled on a cup holder don't survive to the office. Tie each patch's numbers to a photo and a location.

That last point is the reason we built Jobsite Reel. On a lot walk you create a folder, add an asphalt area, type the length, width and depth, and the app shows square feet and tons on the spot using the same SF ÷ 159 × depth formula, along with iPhone photos, notes and a GPS pin. The PDF report totals quantities by folder and maps every numbered area on a satellite view. If you also price curb or flatwork, the same walk covers it; see our curb and gutter calculator and sidewalk replacement cost guide.

Want to compare options first? See pricing or our SiteCam vs Jobsite Reel comparison.

Frequently asked questions

What is the formula for asphalt tons?

A common contractor formula is tons = square feet ÷ 159 × compacted depth in inches. It is the same as square feet × depth ÷ 12 × density ÷ 2,000 with a density of about 151 lb per cubic foot, or roughly 113 lb per square yard per inch. Add a waste allowance on top.

How many tons are in a cubic yard of asphalt?

About 2 tons of compacted hot-mix asphalt. A cubic yard is 27 cubic feet, so at about 151 lb per cubic foot it weighs about 4,075 lb, or 2.04 tons. Mixes vary, so use the unit weight from your plant's mix design when you have it.

How many tons of asphalt do I need for 100 square feet?

Using the SF ÷ 159 × depth rule, 100 square feet takes about 0.63 tons per inch of compacted depth: about 1.26 tons at 2 inches and 1.89 tons at 3 inches, before waste.

Should I use 110 or 115 lb per square yard inch?

Both are common rules of thumb for compacted hot-mix asphalt, and the SF ÷ 159 rule sits between them at about 113 lb per square yard inch. The difference is about 4 to 5 percent. If your supplier or the project spec gives a unit weight or spread rate for the mix, use that instead.

Do I measure loose or compacted depth when calculating asphalt tons?

Use the finished, compacted depth. Asphalt is bought by weight, and the weight does not change when it is rolled, but loose mix is laid thicker than the finished depth so it can compact down. Calculating from loose depth overstates the tonnage.

How much waste should I add to an asphalt order?

It depends on the job. Many crews add a few percent to cover uneven base, feathered edges and handwork; this calculator defaults to 5 percent. Measure depth in several places on patches and raise the allowance where the base is irregular.