Asphalt Calculator

What it calculates and who it’s for

What it estimates and who it is for

This calculator converts a driveway, path, or parking pad into tons of hot-mix asphalt, the unit asphalt plants and paving contractors sell by. It’s for homeowners checking a paving quote and for small paving jobs. It covers hot-mix asphalt only; for a crushed-stone driveway or the stone base under asphalt, use the Gravel Calculator.

How to use

Step by step

Enter the length and width of the area in feet.
Enter the compacted thickness in inches. Choose two layers if you’re placing a base course and a surface course.
Leave the spread rate at 110 unless your plant gives you a different figure (it’s under Advanced, with the extra allowance).
Read the tons to order.

The formula

Every variable and unit

Area (sq yd) = Length (ft) × Width (ft) ÷ 9
Tons = Area (sq yd) × Compacted thickness (in) × Spread rate (lb per sq yd per in) × (1 + Extra % ÷ 100) ÷ 2,000
Tons to order = Tons rounded up to the next half ton
Compacted volume (cu ft) = Length × Width × Thickness ÷ 12 × (1 + Extra % ÷ 100); cubic yards = cu ft ÷ 27

The 110 lb per square yard per inch spread rate is the planning figure Texas and Virginia DOT specifications use to relate tonnage to compacted thickness, and Indiana DOT notes that 110 lb per sq yd is about 1 in of compacted depth for typical mixes. It works out to about 146.7 lb per cubic foot. Actual mixes weigh a little more or less, so the rate is editable.

Worked example

Real numbers, worked by hand

A 40 × 12 ft driveway, 3 in compacted, one layer, 110 lb rate, 5% extra:

Area: 40 × 12 = 480 sq ft ÷ 9 = 53.33 sq yd
Weight: 53.33 × 3 × 110 = 17,600 lb
With 5% extra: 17,600 × 1.05 = 18,480 lb ÷ 2,000 = 9.24 tons
Order: rounded up to the next half ton, 9.5 tons
Volume: 480 × 3 ÷ 12 × 1.05 = 126 cu ft = 4.67 cu yd

With no extra allowance the same driveway is exactly 8.8 tons, so 9 tons to order.

How to read your results

Rounding and buying tips

Tons to order is rounded up to the next half ton. Plants and contractors usually quote and deliver by the ton; ask about minimum loads.
Compacted volume shows the same asphalt in cubic yards or cubic feet; switch units at the top of the results.
With two layers, Layers splits the tons between the base and surface courses, which are often different mixes.

Assumptions and limits

What this estimate does not cover

The area is a rectangle with an even compacted thickness. Add separate areas for turnarounds and aprons.
The spread rate is a planning value for dense-graded mixes. Plants publish their own mix weights; ask for yours and enter it under Advanced.
The 5% extra is our estimate for uneven base and edges, not a published figure.
It doesn’t estimate the stone base, tack coat, or sealer, or tell you how thick a driveway must be. Thickness depends on the soil, the base, and the traffic; check local requirements and your contractor’s recommendation.

FAQ

4 questions

How many tons of asphalt do I need?

Multiply the area in square yards by the compacted thickness in inches and by 110 lb, then divide by 2,000. A 40 × 12 ft driveway at 3 in is 53.33 × 3 × 110 ÷ 2,000 = 8.8 tons before any extra.

How much does a ton of asphalt cover?

At 110 lb per square yard per inch, a ton covers about 18.2 sq yd (164 sq ft) at 1 in compacted, about 9.1 sq yd (82 sq ft) at 2 in, and about 6.1 sq yd (55 sq ft) at 3 in.

How much does asphalt weigh per cubic yard?

110 lb per sq yd per inch works out to about 146.7 lb per cu ft, or about 3,960 lb (1.98 tons) per compacted cubic yard. Your plant’s mix may differ.

Is this different from the gravel calculator?

Yes. Gravel is crushed stone sold by the ton at a different density. Many driveways have both: a gravel base under the asphalt. Estimate them separately.

Tons for common driveway sizes

Reference

All rows use one layer, the 110 lb per sq yd per inch rate, and 5% extra. Tons to order are rounded up to the next half ton.

Driveway (ft)	Area (sq ft)	2 in: tons	2 in: order	3 in: tons	3 in: order
20 × 10	200	2.57	3	3.85	4
40 × 12	480	6.16	6.5	9.24	9.5
50 × 20	1000	12.83	13	19.25	19.5
60 × 24	1440	18.48	18.5	27.72	28
100 × 12	1200	15.4	15.5	23.1	23.5

Your results

Amount

Layers

Area