Asphalt Calculator

How to calculate how much asphalt you need

Hot-mix asphalt is sold by the ton, so the job is to turn an area and a thickness into weight. Measure length and width in feet and the compacted thickness in inches, then:

Cubic yards = length (ft) × width (ft) × thickness (in) ÷ 324
Tons = cubic yards × 1.9575 (145 lb/ft³ compacted)
Shortcut: tons = area (ft²) × thickness (in) × 145 ÷ 24,000

Used as an asphalt estimator, the same tonnage is the base of any budget: multiply it by your price per ton on the asphalt driveway cost page.

The 324 is 12 inches per foot × 27 cubic feet per cubic yard. The 24,000 in the shortcut is 12 inches per foot × 2,000 lb per ton. The calculator above runs the same math and shows cubic feet, cubic meters and metric tonnes too.

The density is the number that matters. This calculator uses 145 lb/ft³, which equals 108.75 lb per square yard per inch. A paving checklist from the Pennsylvania Asphalt Pavement Association, hosted by Penn State, says a typical compacted asphalt mix weighs 108 to 120 lb per square yard per inch, or 144 to 160 lb/ft³, and works its own examples at 110 lb per square yard per inch. The same document tells crews to check the job mix formula (JMF) for the actual figure, because density changes with the aggregate’s specific gravity, the binder content and in-place density. If your plant gives you a weight per square yard per inch, multiply your square yards by that figure and by the thickness instead.

How many tons of asphalt for common sizes?

Most people search with their own dimensions. The table below uses 145 lb/ft³ and compacted thickness. Every figure comes from the site’s calculation library.

Two patterns make the table easy to extend. Each inch of thickness adds 6.04 tons per 1,000 ft², so a 2.5 in layer on 1,000 ft² is 15.1 tons. And tonnage scales straight with area, so 3,000 ft² at 3 in is three times the 1,000 ft² row: 54.38 tons.

How much does a ton of asphalt cover?

At 145 lb/ft³ a ton of hot mix is 13.79 ft³, about 0.51 yd³. How far it goes depends only on thickness.

Use the coverage column to sanity-check a quote. If a contractor proposes 10 tons for a 720 ft² drive, that is 72 ft² per ton, which sits between the 2 in and 3 in rows: roughly 2.3 in of compacted asphalt. Ask which thickness they mean before you sign.

Paving crews think in lineal feet per ton for a given mat width. The Pennsylvania checklist’s yield table, built on 110 lb per square yard per inch, lists 6.8 ft of a 12 ft wide mat per ton at 2 in. At this calculator’s 145 lb/ft³ the same mat runs about 6.9 ft per ton, so the two methods agree to within about 1.5%.

What density should I use for asphalt?

Use the density from your plant’s mix design when you have it. When you do not, 145 lb/ft³ (108.75 lb per square yard per inch) is a reasonable planning value inside the published 144–160 lb/ft³ range for compacted mix.

The spread is not trivial. On 1,000 ft² at 3 in, 144 lb/ft³ gives 18 tons and 160 lb/ft³ gives 20 tons. The checklist says the weight varies with the specific gravity of the aggregate, the asphalt binder (AC) content and the in-place density, so check the mix design (JMF) for your project to get the figure for your mix. The checklist gives the plant method: take the maximum theoretical density in lb/ft³ from the JMF, multiply by 0.75 to get pounds per square yard per inch at 100% density, then by 0.94 for an assumed 94% in-place density.

That method shows why compaction matters to tonnage: the same mix rolled to a higher density puts more pounds into each square yard. If your contractor specifies a target density, the tons per square yard follow from it, and the tons to cubic yards converter will move between the two units once you have a weight per yard.

Asphalt per square metre (metric)

Outside the US asphalt is ordered in tonnes and layer thickness is given in millimetres. At 145 lb/ft³ asphalt is about 2,323 kg/m³.

A 5 × 4 m area at 50 mm is 1 m³, about 2.32 tonnes. A 6 × 10 m drive at 60 mm is 3.6 m³, about 8.36 tonnes. Surface courses and base courses often use different mixes with different densities, so check each layer’s figure with the supplier.

Asphalt for driveways, parking lots and roads

The math is the same at every scale; what changes is how many layers you size and how many tons a truck carries.

Driveways. A residential drive is usually one or two layers of hot mix over a compacted stone base. Size each asphalt layer separately at its own compacted thickness and add them. Thickness is a design decision that depends on the soil, the base and the vehicles, so take it from your contractor’s proposal rather than from a rule of thumb. What the calculator shows is the cost of each inch: on a 12 × 60 ft drive, every inch of asphalt is about 4.35 tons.

Parking lots. The Pennsylvania checklist works a 150 × 300 ft lot at 3 in: 5,000 yd² × 3 in × 110 lb ÷ 2,000 = 825 tons. At 145 lb/ft³ this calculator gives 815.63 tons for the same lot. On jobs this size the 1.1% difference is about 9 tons, roughly half a truckload, so bids use the job mix density.

Roads and lanes. A 12 ft lane one mile long is 63,360 ft². At 1.5 in compacted it takes about 574 tons, and at 2 in about 766 tons. The checklist’s answer for the 1.5 in lane, using its yield table, is 581 tons.

Truckloads. Load size depends on the truck and on local legal weights, so ask the plant. The checklist uses a 22-ton load as its example: 22 tons × 6.8 ft per ton = 150 ft of a 12 ft lane at 2 in. At this calculator’s 145 lb/ft³ the same load covers about 1,821 ft², or about 152 ft.

Does asphalt need extra for compaction?

No separate compaction allowance is needed when you size with the compacted thickness and a compacted density, because the tons already describe the rolled mat. Asphalt is spread loose and thicker than the finished layer, then rolled down, but the weight does not change during rolling, only the thickness.

The mistake is mixing the two states. If you measure a loose depth (for example, the screed setting) and multiply by a compacted density, you overstate the tonnage. If you measure the finished thickness and multiply by a loose density, you understate it. Keep both numbers compacted.

You still need an allowance for waste: edges that run wide, low spots in the base that fill with extra mix, tie-ins to existing pavement and material left in the truck. The calculator defaults to 10% and you can change it. On a well-prepared, square job a smaller allowance may be enough; on irregular or patched surfaces you may want more.

Small patches and potholes

For small repairs the same formula works in pounds. A 4 × 6 ft patch at 3 in is 6 ft³, about 870 lb, or 0.44 tons of hot mix. A 2 × 2 ft pothole filled 2 in deep is about 97 lb. Bagged cold patch is sold by weight, so divide the pounds by the bag weight and round up. Cold patch products state their own coverage on the bag; use that when it differs from this estimate.

How to measure an area for asphalt

Measure the finished paved surface, not the dirt you can see before the job. Asphalt is laid over a prepared base, and the paved edge is where the tonnage ends.

Rectangles. Length × width in feet. A drive that is 12 ft wide and 60 ft long is 720 ft², or 80 yd² (divide square feet by 9). Plants and paving crews often work in square yards, so it helps to have both.

Flared aprons and turnarounds. Split them into a rectangle plus triangles. A triangle is half of base × height: a flare that widens a 12 ft drive to 18 ft over 6 ft of length adds two triangles of 3 × 6 ÷ 2 = 9 ft² each, 18 ft² in all. At 3 in compacted that is about 0.33 tons.

Curves and circles. The area of a circle is 3.1416 × radius². A 20 ft diameter turning circle is 314.2 ft², which at 2 in compacted is about 3.8 tons.

Thickness. Use the compacted thickness from the proposal or plans for each layer. If the proposal lists a base course and a surface course, run the calculator once for each and add the tons. Mixes with different aggregates can have different densities, so if the plant gives a figure for each, use it per layer.

When the total is in, round up to what the plant can load. Hot mix has to be laid and compacted while it is still hot, so ask the plant about minimum loads and whether it takes returns; the 10% allowance is the place to decide how close you want to cut it.

Common mistakes when ordering asphalt

Most asphalt estimates go wrong in units and thickness, not in arithmetic. These are the errors that cost the most, with their size on real jobs.

• Entering thickness in feet. The 324 formula expects inches. A 10 × 10 ft area at 3 in is 1.81 tons; typed as 3 ft it becomes 21.75 tons, twelve times too much.
• Mixing loose and compacted depth. Size with the finished, compacted thickness. A loose depth multiplied by a compacted density overstates the order.
• Treating 145 lb/ft³ as exact. The published range for compacted mix is 144–160 lb/ft³. On a 12 × 60 ft drive at 3 in that is 12.96 to 14.4 tons. Ask the plant for its density per square yard per inch.
• Ordering cubic yards when the plant sells tons. One cubic yard of compacted asphalt is about 1.96 tons. A 12 × 60 ft, 3 in drive is 6.67 yd³ but 13.05 tons; ordering “6.67 tons” would deliver about half of what it needs.
• Rounding thickness down. Going from 2 in to 3 in on 1,000 ft² raises the order from 12.08 to 18.13 tons, 50% more. Agree the finished thickness with your contractor first.
• Forgetting the base. The stone base under asphalt is a separate order sized by its own depth and weight per yard. Use the crusher run calculator or the driveway gravel calculator for it.
• Measuring odd shapes as one rectangle. Split L-shapes and turnarounds into rectangles and add them. For a circle, area is 3.1416 × radius².

Asphalt calculator vs driveway gravel, crusher run and concrete calculators: which one to use

This calculator sizes hot-mix asphalt by the ton from compacted thickness. Use a different tool for the layers and alternatives around it:

• Crusher run calculator: the dense-graded stone base that usually goes under asphalt, with compacted-weight guidance.
• Driveway gravel calculator: a full gravel driveway built in layers, if you are choosing gravel instead of paving.
• Concrete driveway calculator: cubic yards and bags for a concrete drive. For comparison, a 12 × 60 ft drive at 4 in is 8.89 yd³ of concrete.
• Asphalt driveway cost: turn the tonnage into a budget with your price per ton, cost per square foot, overlay vs new, sealcoat and asphalt vs concrete.
• Gravel driveway cost: how to turn a gravel tonnage into a budget with your own local quotes.
• Square feet to cubic yards: plain area-and-depth conversions for any material.