Asphalt Calculator

Compacted in place, not loose in the truck

Read this before you enter anything. Thickness here is the COMPACTED thickness in place, and the unit weight is an in-place figure. Neither describes the loose mix in the truck bed, which is lighter per cubic foot and thicker before the roller passes.

Hot mix arrives loose, thicker than it will finish, and only reaches its published weight once it is rolled. Of the six calculators ranking for asphalt calculator, none says which state its density describes and none cites a document for it.

The Asphalt Institute method, worked

The formula is the Asphalt Institute’s: thickness in feet, times area, times unit weight, divided by 2,000. Their own example reads:

10' x 25' x (4/12)' = 83.3 cubic feet of HMA ... 83.3 cubic feet x 148 PCF = 12328 pounds of mix = 12328 / 2000 tons = 6.1 tons

This page loads in that example. The sheet returns 83.33 cubic feet and 6.17 short tons where the source prints 6.1: it rounds the volume to 83.3 before multiplying, and 12,328 divided by 2,000 is 6.16, not 6.1.

Area        A  =  L x W        rectangle
               =  pi x D^2 / 4  circle
               =  B x H / 2     triangle   (sum every area)
Per course  V  =  A x t / 12                (sq ft, inches -> cu ft)
Weight      Wt =  V x UW                    (UW = lb per cu ft, in place)
Short tons  T  =  Wt / 2000
Section     Ts =  sum( T ) over the courses
Order       To =  Ts x (1 + overage / 100)
Spread rate R  =  UW x 9 / 12               (lb per sq yd per inch)
Loads       N  =  ceil( To / payload )      (only if you enter one)

Unit weight, spread rate and the 110 figure

Only two published figures sit behind the preset selector:

• Asphalt Institute, 142 to 148 lb per cubic foot in place. Their engineering FAQ reads: Asphalt Mixture typically weighs from 142 to 148 pounds per cubic foot (PCF) in-place. Use 148 PCF. — read it here.
• 110 lb per square yard per inch, compacted. The Minnesota Asphalt Pavement Association states it on its own calculator as Assume Compacted Asphalt Pavement Unit Weight: = 110 LB/(SY*INCH) — read it here. Texas’s 2024 specification for dense-graded mixes uses the same rate: The thickness determined is based on the rate of 110 lb. per square yard for each inch of pavement, unless otherwise shown on the plans. — Item 341. Converted, it is 146.67 lb per cubic foot.

A spread rate is a unit weight seen from above: pounds per cubic foot times 9, divided by 12. The two figures land within one pound of each other, 111 against 110.

Courses: surface, binder and asphalt base

None of the six ranking calculators will add a second lift. This sheet takes off up to three courses — surface course, binder course and asphalt base course — each with its own compacted thickness and, if the plant quotes a different mix, its own unit weight. Aggregate base under the asphalt is not in this takeoff; it goes through sheet C-101.

Checking a paver’s quote

The spread rate turns a bid back into a quantity. If a proposal says 48 tons for a 960 sq ft drive, 48 tons is 96,000 lb over 107 square yards, about 900 lb per square yard, which at 111 lb per square yard per inch is roughly 8.1 inches compacted.

Worked example: a 24 by 40 ft drive in two lifts

1. Area: 40 ft x 24 ft = 960 sq ft, or 107 sq yd.
2. Surface course, 1½ in compacted: 8.88 short tons.
3. Binder course, 2 in compacted: 11.84 short tons.
4. Section total, 3.5 in of asphalt: 20.72 short tons, or 18.8 metric tonnes.
5. At a 20 ton payload that is 2 loads.
6. At a $110 per ton quote the mix alone is $2,279.20.

Frequently asked

How do I calculate how much asphalt I need?

Area in square feet, times the compacted thickness in inches, divided by 12, times the unit weight in pounds per cubic foot, divided by 2,000. The 960 sq ft driveway above at 3.5 inches works out to 20.72 short tons.

How much does 1 ton of asphalt cover 3 inches thick?

About 54 square feet, or 6 square yards, at 148 lb per cubic foot compacted. The coverage table above gives 1½, 2 and 4 inches.

How many tons is 1 yd of asphalt?

A cubic yard of compacted mix is 27 cubic feet, so at 148 lb per cubic foot it weighs 3,996 lb, or about 2 short tons.

Is 2 inches of asphalt enough?

A calculator should not answer that: thickness comes from your plans, your local agency’s standard detail or the paver’s specification. What the sheet gives is the price of the question: over 960 sq ft, each extra inch of compacted mix is 5.92 more tons.

Limits of this sheet

This sheet does not suggest a thickness, a lift depth, a tack-coat rate or a compaction factor: no open document was read for any of them. Take them from your plans, your specification or the plant.

Overage, truck payload and price start blank for the same reason. C-201 converts flat plan areas and compacted thicknesses into a mass of hot mix; it does not design a pavement section, choose a mix or account for a crowned or sloped surface. Both unit weights are published figures for asphalt in general, not a measurement of your plant’s mix. Quantities are for planning and ordering, not engineering.

Sheet C-201 prepared by TakeoffMetric Editorial; no author, credential or field measurement is claimed.