Asphalt Calculator

The formula

• Area (sq ft) = Length × Width, or π × Diameter² ÷ 4, times the number of identical areas.
• Square yards = Square feet ÷ 9.
• Compacted volume (cu ft) = Square feet × Thickness (in) ÷ 12. Cubic yards = Cubic feet ÷ 27.
• Spread rate (lb/sq yd) = Thickness (in) × Unit weight (lb/sq yd/in).
• Weight (lb) = Square yards × Spread rate. A density in lb/cu ft gives the same weight as Volume (cu ft) × Density, because 1 sq yd × 1 in = 9 sq ft × 1/12 ft = 0.75 cu ft, so 1 lb/sq yd/in = 4/3 lb/cu ft exactly.
• With your mix’s Gmm: Spread rate (lb/sq yd) = Thickness (in) × Gmm × 43.3, then Weight = Square yards × Spread rate.
• US short tons = Pounds ÷ 2,000. Metric tonnes = Pounds × 0.45359237 ÷ 1,000.
• Tons with overage = Tons × (1 + Overage ÷ 100). Cost = Tons ordered × Your price per ton.
• Tons to area: Square yards = Tons × 2,000 ÷ (Thickness (in) × Unit weight).

Thickness is the compacted thickness

Enter the finished, rolled thickness: the thickness on the plan. The per-inch state figures on this page are per inch of that thickness. INDOT’s table is headed “Pavement Thickness”, and FDOT’s equation defines t as the plan thickness or the individual layer thickness. The loose mat behind a paver is thicker than the finished layer, so entering it here would overstate the tons.

Why the weight basis is yours

The weight of a compacted layer depends on the mix: the specific gravity of its aggregate, its binder content and its air voids after rolling. That is why FDOT’s equation takes Gmm, the maximum specific gravity, from the mix design. FDOT’s July 2015 Section 334 based pay quantities on “the actual maximum specific gravity of the mix being used.”

The state documents read for this page print different figures for different mixes, so no single figure is built in, and none is applied unless you choose it. The calculator opens on your own figure, from your plant’s mix design or your state’s specification. Enter a lower and an upper figure and the answer is a range, never an average.

The state agency planning factors

The weight basis can also be one of six per-inch figures from three state DOT documents, listed with each document and date in the reference table below the worked example. They are opt-in: the calculator opens on your own figure and applies one of these only when you choose it. Each is the figure a state DOT uses to estimate quantities on its own plans. Each is an agency factor for its own mix or scope, not a universal asphalt density and not your mix. None is a measured density.

Five of the rows name a mix: Illinois DOT District One’s HMA surface mixtures and NCDOT’s S9.5B, S9.5C/S9.5D, I19.0C and B25.0C. Indiana DOT’s is one factor for all asphalt mixtures, with no mix type named. So its option is called an estimating convention and says it covers all mixes; the others are called planning factors and name their mix.

Choose one only if your plans or contract use it; the note under the result repeats its document, date and scope. If your plans give another figure, enter it as your own unit weight, in lb/sq yd/in.

• Indiana DOT, Indiana Design Manual, Ch. 17, Figure 17-4A (Rev. Sep. 2021): 110 lb/sq yd per inch, printed as 0.055 tons per square yard at 1 in. One factor covers all “Asphalt Mixtures”; no mix type is named.
• Illinois DOT District One, HMA Mix Selection Guide (revised 6/1/2023): 112 lb/sq yd/in, “the unit weight used to calculate all HMA surface mixture quantities.” A District One guide; a statewide IDOT figure was not found in the sources reviewed.
• NCDOT, Pavement Design Procedure, “Unit Weights; Application Rates” (January 4, 2019): S9.5B 110; S9.5C/S9.5D 112; I19.0C 114; B25.0C 114 lb/sq yd/in. NCDOT’s Roadway Design Manual 6-1D, “Pavement Schedule” (rev. 07/18/18) gives the same rates as the “rate to be used for calculation of quantities”.

What the figures span

The per-inch unit weights printed in the INDOT, IDOT District One and NCDOT documents read for this page run from 90 lb/sq yd/in, for NCDOT’s PADC (permeable asphalt drainage course), to 114 lb/sq yd/in, for NCDOT’s I19.0C and B25.0C: 120 to 152 lb/cu ft. The six in the reference table span 110 to 114 lb/sq yd/in (146.67 to 152 lb/cu ft).

These documents also print per-inch unit weights for other mixes, including: NCDOT’s PADC (permeable asphalt drainage course) at 90 lb/sq yd/in (Pavement Design Procedure, “Unit Weights; Application Rates”, January 4, 2019); NCDOT’s S4.75A at 100 lb/sq yd/in (Roadway Design Manual 6-1D, “Pavement Schedule”, rev. 07/18/18); and Illinois DOT District One’s Polymerized HMA Binder Course IL-4.75, N50 at 110 lb/sq yd/in (HMA Mix Selection Guide, revised 6/1/2023). NCDOT’s Roadway Design Manual also lists OGAFC, Type FC-1 Modified, in its per-inch column as “70-90 Lbs/SY”, a rate per square yard, so it is not counted. Illinois DOT District One’s guide also prints 112 lb/sq yd/in for the HMA binder course items it lists. None of these is offered as a weight basis.

INDOT’s table also lists factors for other thicknesses, and some of those rows are rounded: it prints 140 lb/sq yd for 1.25 in, where 110 × 1.25 = 137.5. The reference table gives its per-inch factor only.

If a figure you enter falls outside the full span, 90 to 114 lb/sq yd/in, the calculator shows a warning. It is a check on the unit, not on your mix: pounds per cubic foot are 4/3 of pounds per square yard per inch, and pounds per cubic yard are 27 times pounds per cubic foot.

Florida’s Gmm equation

Florida DOT’s Section 334-1.5, Asphalt Concrete for LAP (FY 2026-27, REV 12-15-25) gives Spread rate (lbs/yd²) = t × Gmm × 43.3, where t is the thickness in inches and Gmm is the maximum specific gravity from the mix design. It is written for Local Agency Program (off-system) projects. The current on-system Section 334 was not read.

43.3 is not a pure unit conversion. FDOT’s July 2015 Section 334, now superseded, says the conversion rests on the mix’s Gmm as well as the minimum density level. FDOT rounds the spread rate to a whole number for target purposes only; the calculator does not round it.

The 2015 edition also said plan quantities were based on a Gmm of 2.540, corresponding to 110 lbs/yd² per inch (2.540 × 43.3 = 109.982). That is historical context for the equation. It is not offered as a choice.

The pay unit in these documents

Each of the INDOT, IDOT District One, NCDOT, FDOT LAP and SCDOT documents read gives the ton as the pay unit for the asphalt items it covers. INDOT’s statement is scoped: its Design Manual Chapter 17 says “The pay unit is ton” for HMA pavement replaced where pipe is placed under existing pavement (its “HMA for structure installation”). Illinois District One’s mix table gives the pay unit as TON. NCDOT’s asphalt concrete pay items are in tons. FDOT’s LAP Section 334-8 gives the quantity to be paid for as the weight of the mixture, in tons. SCDOT’s Plan Preparation Guide, Chapter 3, works tons from an application rate taken from the pavement design: 13,540 SY × 175 lb per SY ÷ 2,000 = 1,185 tons as printed (1,184.75 before rounding). Vermont’s Estimating Quantities page works in metric tons.

Two of those documents show the ton is 2,000 lb: INDOT prints 110 lb/yd² as 0.055 T/yd² (110 ÷ 2,000), and SCDOT divides pounds by 2,000. The calculator reports US short tons of 2,000 lb, with metric tonnes beside them.

Other figures read

Vermont AOT’s “Estimating Quantities” page, a metric page, estimates plant mixed base course at 2.462 metric tons per cubic meter (153.7 lb/cu ft; 115.27 lb/sq yd/in), and converts bituminous concrete gutters, traffic islands and sidewalk with the same figure. Beside its pavement items it prints an annotation of 2.4 metric tons per cubic meter (149.83 lb/cu ft; 112.37 lb/sq yd/in). Vermont gives neither as the density for its pavement items: for those it defers to its Materials section, and the 2.4 is a bracketed annotation of unclear standing. Neither is a per-inch figure, so neither is in the reference table, and neither is counted in the per-inch span above.

VDOT’s 2025 pavement design guide for subdivision and secondary roads gives application rates in pounds per square yard from the pavement design. A per-inch factor was not found in it. SCDOT’s guide takes its rate from the field review or pavement design in the same way.

Sources read

Each was read on 2026-09-29, from the document’s own text or from its rendered pages, and is listed with the site it is published on. The five that the weight-basis options, the reference table, the unit check and the Gmm equation rest on also have a full source record on this page, with a link and the kind of figure it is.

• Indiana Department of Transportation, Indiana Design Manual, Chapter 17 Quantity Estimating, Figure 17-4A Roadway Quantities Factors, Rev. Sep. 2021 (in.gov).
• Illinois Department of Transportation, District One, HMA Mix Selection Guide, revised 6/1/2023 (apps1.dot.illinois.gov).
• North Carolina Department of Transportation, Pavement Design Procedure, “Unit Weights; Application Rates”, January 4, 2019 (connect.ncdot.gov).
• North Carolina Department of Transportation, Roadway Design Manual 6-1D, “Pavement Schedule”, rev. 07/18/18 (connect.ncdot.gov).
• Florida Department of Transportation, Section 334 Asphalt Concrete for LAP, 334-1.5 and 334-8, FY 2026-27, REV 12-15-25 (fdotwww.blob.core.windows.net).
• Florida Department of Transportation, Section 334 Superpave Asphalt Concrete, 334-1.4, in the superseded July 2015 specification book (fdotwww.blob.core.windows.net).
• Vermont Agency of Transportation, Estimating Quantities, a metric web page dated only by its 2026 copyright (vtrans.vermont.gov).
• Virginia Department of Transportation, Pavement Design Guide for Subdivision and Secondary Roads in Virginia, revised 2025 (vdot.virginia.gov).
• South Carolina Department of Transportation, Plan Preparation Guide, Chapter 3 Quantity Computations, undated; its PDF metadata gives 2005-09-06 (scdot.org).