Asphalt Calculator — Compaction Changes the Thickness, Not the Tons

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This selector governs every field, label, result and export here and takes priority over the site header switch. Switching converts what you entered rather than reinterpreting it, so a 50 ft length becomes 15.24 m and returns to exactly 50.

The Area

The dimensions asked for below follow from this answer. A driveway is usually one rectangle, a car park is usually several, and a figure from a drawing or a survey goes in the third route directly.

The Thickness and the Density

In inches, and it is the finished depth after rolling. Not the depth the paver spreads: that is 10 to 15 percent thicker and entering it produces a tonnage nobody ordered.

Three answers and exactly one runs. A planning band returns a tonnage range because the source gives a range. A figure from the job mix formula replaces it outright. A Rice value with a specified compaction runs the published Asphalt Institute derivation.

The Order

It covers shortage, delivery, rounding and field variation, and it is not a compaction allowance. Published guidance gives 5 to 10 percent, and the reason stated is that nobody likes running short with a hot paver waiting. None is an answer and is offered as one.

The Lift Checks and the Extras (all optional)

In inches, from the mix designation. Published Asphalt Institute guidance gives a lift thickness of 3 to 4 times it for dense graded mixes, and this page checks each lift against that band rather than the total.

As a percentage, for the depth the paver spreads. Published guidance puts the placed lift at 10 to 15 percent above compacted. It is a screed setting and it touches no tonnage figure on this page.

In inches, where the job has more than one course. Each lift is computed on its own and reports its own order tonnage.

In pounds per cubic foot. A lift entered with a thickness and no density is reported as incomplete rather than given the first lift figure, because base, binder and surface courses are different mixes.

In inches, where the job has a third course. Same contract as the second lift: its own thickness, its own density, its own order.

In pounds per cubic foot, for the third course.

In gallons per square yard, from your specification. This page holds no published tack rate of its own and applies only the figure you bring.

Required where a tack rate is entered. Between lifts multiplies by the number of lifts on the form, because a job tacked before every course is tacked more than once and a single application would undercount it.

Per US ton, in your own currency. Arithmetic only: no haul, no mobilisation, no tack and no tax.

Overview

A roller does not create asphalt. It moves the same mass into less space.

That single fact separates this page from the Gravel Calculator next to it. Gravel is bought by volume, a volume shrinks under a roller, and the order carries a compaction multiplier. Asphalt is bought by the ton, mass does not shrink, and no compaction factor belongs on the tonnage at all.

The compaction figure on this subject is real and it lives somewhere else. The paver spreads a lift 10 to 15 percent thicker than the finished depth. That number tells the screed what to do and changes nothing about what you order.

The second thing most calculators get wrong is the density, and the reason is that they treat it as a constant. Published Asphalt Institute guidance derives it: the mixture's Rice value times 62.4 gives the solid density, and the specified percent compaction gives the acceptable unit weight. A typical Rice value of 2.500 gives 156.0 pounds per cubic foot, which at 95 percent is 148.2 and at 93 percent is 145.1.

So the 145 and the 148 that circulate as competing standard figures are one mix at two specified compactions.

And the cubic yard conversion is published three ways for the same density. 1.96 is compacted and reproduces. 1.4 is stated for loose material. 2.4 is stated against the same 145 pounds and would need 178, which is above every published band, and following it over-orders by about 23 percent.

What to Look at First

Read the density line before you read the tonnage. Where it came from a planning band the tonnage above it is a range, and the range is real: on 1,000 square feet at 3 inches the published band alone moves the order from 17.75 tons at 142 pounds to 18.50 at 148, which is 4.2 percent on a job where the waste allowance might be 5. A figure from the job mix formula collapses that to one number, and so does a Rice value with a specified compaction.

Then read the thickness field and check it is the compacted one. The commonest published error on this subject is entering the depth the paver spreads, which is 10 to 15 percent greater and produces a tonnage nobody ordered. The loose figure has its own field further down and it reaches the placed depth only.

Then read the cubic yard block as a check rather than as an order. Asphalt is quoted and delivered by the ton. The volume is there so you can test a quote against it, and every figure in it is named as compacted, because two of the three conversions in circulation describe different states of the same material and the third describes nothing at all.

How to Use This Calculator

  1. Enter the compacted thickness, not the depth the paver spreads. The placed lift is 10 to 15 percent thicker and entering it produces a tonnage nobody ordered. If the figure you have is a screed setting, it belongs in the loose thickness factor further down instead.

  2. Say where the density comes from. A planning band for the mix is the default and it returns a range, because the published source gives a range and choosing a point inside it is not this page's decision. A figure from your job mix formula beats it outright. And if you have a Rice value and a specified compaction, the page applies the published derivation to them, because that is where 145 and 148 come from in the first place.

  3. Enter the nominal maximum aggregate size if you know it. The page checks each lift against the published 3 to 4 times ratio, and it checks the lifts rather than the total. A total inside the band can contain a lift below it.

  4. Enter each lift separately where the job has more than one. A binder course and a surface course are different mixes at different densities, bought as different orders, so each one reports its own tonnage and its own order.

  5. Read the cubic yard figure as a check, not as an order. Asphalt is bought by the ton and the volume is there so you can test a quote against it. Three conversions circulate for one density and the result says what each of them is.

  6. Take the base course to the Gravel Calculator. It carries a compaction multiplier that is correct there and would be wrong here, and a reader who took this page's no compaction rule to a base would under-order the stone by about a third.

Inputs & Outputs

Inputs

•Unit System : Options: US / Imperial (ft, in, lb/cu ft, tons), SI / Metric (m, mm, kg/cu m, tonnes)
•How the Area Is Entered : Options: Not selected, A rectangle, from a length and a width, Several rectangles summed, An area already known
•Length
•Width
•Area 1 Length
•Area 1 Width
•Area 2 Length
•Area 2 Width
•Area 3 Length
•Area 3 Width
•Area
•Compacted Thickness
•Where the Density Comes From : Options: Not selected, The planning band for a mix type, A density I will enter, Calculated from a Rice value and a specified compaction
•Mix Type : Options: Not selected, Hot mix asphalt, 145 to 150 lb per cu ft, Warm mix asphalt, 142 to 148 lb per cu ft, Dense graded, 148 to 152 lb per cu ft, Open graded, 135 to 142 lb per cu ft, Stone matrix asphalt, 140 to 145 lb per cu ft
•Density
•Rice Value
•Specified Percent Compaction
•Waste Allowance : Options: Not selected, Five percent, the published low end, Ten percent, the published high end, A stated percentage, None
•Stated Waste Percentage
•Nominal Maximum Aggregate Size
•Loose Thickness Factor
•Second Lift Compacted Thickness
•Second Lift Density
•Third Lift Compacted Thickness
•Third Lift Density
•Tack Coat Rate
•Tack Coat Applications : Options: Not selected, One, Between lifts, A stated number
•Stated Number of Applications
•Price Per Ton

Outputs

•The area, in square feet, square yards and square metres, because the square yard is the unit paving bids use
•The tonnage per lift and in total, with the density used, the source it came from and the published band beside it
•The compacted cubic yard volume and the compacted tons per cubic yard, with the three published conversions and what each one is
•The depth the paver spreads, where a loose factor was entered, and a statement that it changed no tonnage
•The minimum lift band at three and four times the aggregate size, checked against each lift separately rather than against the total
•The coverage per ton and the tons per square foot per inch, both compacted and reported for checking a quote
•The waste allowance on its own line and the order tonnage after it, per lift as well as in total, with the tack coat and the cost where entered
•The boundaries: what this page does not compute and which figures are yours

Asphalt Formula

The area routes.

Area from a rectangle

area_sf = len_ft * wid_ft

Several rectangles summed

area_sf = area_1_sf + area_2_sf + area_3_sf

Square yards

area_sy = area_sf / 9

The tonnage.

Volume in cubic feet

vol_cf = area_sf * thick_in / 12

Tonnage of one lift

tons = vol_cf * dens_pcf / 2000

Tonnage of several lifts

tons_all = tons_1 + tons_2 + tons_3

Order tonnage of one lift

tons_lift_order = tons * (1 + waste_pct / 100)

Order tonnage, all lifts

tons_order = tons_all * (1 + waste_pct / 100)

The density, where it is derived rather than looked up.

Solid density from the Rice value

solid_pcf = rice_gmm * 62.4

Acceptable density at a specified compaction

dens_pcf = solid_pcf * comp_pct / 100

The cubic yard, compacted only.

Compacted cubic yards

vol_cy = vol_cf / 27

Compacted tons per cubic yard

tons_cy = dens_pcf * 27 / 2000

The checking figures.

Tons per square foot per inch

tons_sf_in = dens_pcf / 12 / 2000

Coverage per ton

cover_sf = 2000 / dens_pcf * 12 / thick_in

The thickness the paver spreads, and the lift the stone allows.

Loose thickness the paver spreads

loose_in = thick_in * (1 + loose_pct / 100)

Minimum lift, low end

min_lift_lo_in = agg_max_in * 3

Minimum lift, high end

min_lift_hi_in = agg_max_in * 4

The tack coat.

Tack coat volume

tack_gal = area_sy * tack_rate * tack_apps

Unit conversions. 1 pound per cubic foot is 16.0185 kilograms per cubic metre, 1 US ton is 0.90718474 tonnes, 1 square foot is 0.09290304 square metres and 1 inch is 25.4 millimetres.

There is no compaction factor in the tonnage. Published guidance states that tonnage remains constant regardless of compaction, because a roller changes the volume and not the mass. The thickness entered is the compacted one and the tons follow from it directly.

The loose thickness equation exists for the depth the paver spreads and reaches no tonnage figure. A build applying it to the tons would be ordering mass a roller cannot create.

The density has three sources and exactly one runs. A planning band for the mix type is the default, and because the published source gives a band rather than a figure, the tonnage it produces is reported as a range. A density entered from a job mix formula replaces it outright and is never averaged with it, and it returns one number. And where a reader has a Rice value and a specified compaction, the two density equations apply the association's derivation to them: the Rice value times 62.4 gives the solid density, and the specified percent compaction gives the acceptable unit weight. A Rice value of 2.500 gives 156.0, which is 148.2 at 95 percent and 145.1 at 93, so the two planning figures that circulate are one mix at two specifications.

The page measures no Rice value. It applies the derivation to a figure the reader brings from a mix design, and the result names which of the three sources produced the density it used.

The cubic yard equations are compacted only. No loose tonnage is computed, because the two published loose relationships do not reconcile: one gives loose asphalt as compressing to 75 to 80 percent of its volume and the other gives placed thickness as 10 to 15 percent greater than compacted, which makes compacted 87 to 91 percent of placed.

The minimum lift is two equations rather than one with a ratio in it, because the published guidance gives 3 to 4 times the nominal maximum aggregate size and both ends are the source's. Each lift is checked separately, because a total inside the band can contain a lift below it.

Full precision is kept through every equation and the rounding happens once, at the display.

Compaction Changes the Volume and Not the Mass

The Gravel Calculator on this site carries a compaction multiplier on the order, and it is right to. A base is bought by volume, a volume shrinks under a roller, and the pile has to be bigger than the hole.

This page carries none, and that is not an omission.

Published guidance states it directly: tonnage remains constant regardless of compaction, which is why suppliers and contractors prefer it. Another puts it as an instruction, order by the compacted ton, which is what the formula gives, because the crew lays a thicker loose lift to reach the depth after rolling. No extra tonnage is added for compaction and only the waste allowance is.

A roller does not create or destroy asphalt. It moves the same mass into less space.

There is a compaction figure on the subject and it belongs somewhere else. Published guidance puts the placed thickness at 10 to 15 percent greater than the compacted thickness, and that number tells the paver operator what to set the screed to. It is a thickness, and applying it to the tonnage would order material a roller cannot make.

So the thickness field on this page is labelled compacted, the loose figure is reported separately where a reader wants it, and it touches no tonnage figure anywhere. On a 1,000 square foot job at 3 inches a calculator multiplying the tons by 1.15 would order 20.85 tons against 18.13, which is 2.72 tons of asphalt that does not exist.

One Conversion, Three Published Answers, and One of Them Is Impossible

Asphalt is ordered by the ton and every yard quotes tons per cubic yard, so the conversion matters.

At the planning density of 145 pounds per cubic foot a cubic yard holds 27 cubic feet, weighs 3,915 pounds and is 1.96 tons. Two published sources give that figure and the arithmetic reproduces on both.

A third gives 1.4 tons per cubic yard for loose spread material and up to 2.0 for highly compacted mixes.

A fourth states that there are approximately 2.25 to 2.5 tons in a cubic yard, that hot mix typically weighs 2.4, and prints a conversion table headed as using the standard 145 pound density.

The 1.96 is compacted and reproduces from the density. The 1.4 is stated for loose spread material and this page does not reproduce it, because the two published loose relationships disagree. One source gives loose asphalt as compressing to 75 to 80 percent of its volume. Another gives placed thickness as 10 to 15 percent greater than compacted, which makes compacted 87 to 91 percent of placed. Those are not the same relationship, and until it is settled a loose tonnage derived from either would rest on an open question.

So the 1.4 is reported as published and unreproduced, which is a different thing from reporting it as wrong.

The third is not a state of anything. For a cubic yard to weigh 2.4 tons the material would have to be 177.8 pounds per cubic foot. The widest published band on this page runs from 135 for open graded to 152 for dense graded, and 178 is above all of it.

A reader who takes that table to a supplier over-orders by about 23 percent, on a material that is delivered hot and cannot be returned.

So this page reports the conversion with its state named and shows all three published figures with the reason each is what it is.

The Density Is Derived, Not Looked Up

Every calculator on the subject uses 145 pounds per cubic foot, and it is a reasonable planning figure. It is also not a property of asphalt.

Published Asphalt Institute guidance gives the maximum unit weight as the mixture's maximum specific gravity, the Rice value, multiplied by 62.4 pounds per cubic foot, and then the acceptable unit weight as that figure multiplied by the specified percent compaction. Its own worked example runs a typical Rice value of 2.500 to 156.0 pounds per cubic foot solid, then to a minimum acceptable 148.2 at 95 percent compaction and 145.1 at 93 percent, which is the same statement as a maximum of 7 percent air voids.

So the 145 and the 148 that circulate as rival planning densities are one mix at two specified compactions. The association's own quantity example uses the 148: 83.3 cubic feet times 148 pounds per cubic foot is 12,328 pounds, which is 6.1 tons, and it reproduces.

Underneath the derivation sit the planning bands, and they are trade figures rather than association ones. Published bands give hot mix at 145 to 150, warm mix at 142 to 148, dense graded at 148 to 152, open graded at 135 to 142 and stone matrix at 140 to 145. By course rather than by mix, surface courses with finer aggregate run 143 to 147 and binder courses with coarser aggregate run 146 to 150.

On 1,000 square feet at 3 inches, 142 pounds gives 17.75 tons and 148 gives 18.50. That is 4.2 percent from the density band alone, on a job where the waste allowance might be 5.

So a band on this page returns a band. Choosing a point inside a published range is a decision the source did not make, and a single tonnage is issued only where the reader brings a density or a Rice value with a specification. Every result carries the published instruction beside the figure it used: confirm it with the supplier or the job mix formula, because tonnage changes directly with it.

The Minimum Lift Is Set by the Stone in the Mix

Thickness on this subject is two decisions and most calculators treat it as one.

Total pavement thickness comes from engineering design, traffic loading and local agency specifications. Published guidance says so and this page does not take that decision.

Individual lift thickness has a different constraint, and it comes from the aggregate. Published Asphalt Institute guidance states it in its own words: typically, for dense graded mixes, a lift thickness of 3 to 4 times the nominal maximum size of the aggregate is needed. So a mix with a half inch nominal maximum size wants a compacted lift of 1.5 to 2 inches.

The same source gives the reason, which almost no calculator on the subject carries. Too thin a mat does not have sufficient workability and too thick a mat may be unstable, because the mixture has to have controlled workability to be compacted at all. A lift barely thicker than the stones it contains cannot be worked into a dense mat. Published conference material from a state asphalt association adds the direction, that the ratio is a minimum rather than a maximum, and lists thin lifts being easier to compact as a myth: a thicker lift lets the paver run slower, cools more slowly and gives more room to work the mix into a denser mass.

And the ratio governs each lift rather than the total. Three inches laid as a 1 inch surface over a 2 inch binder, on a half inch aggregate, has a total inside the band and a first lift below it. A calculator checking the total alone passes that job.

So this page takes a nominal maximum aggregate size where a reader has one, reports the minimum lift at both ratios rather than one, checks every lift entered against it separately, and computes the tonnage anyway where a lift is below the band, because the ratio is published as guidance and a reader with a reason is not an error.

This Page Is Not the Base Course

Published guidance is consistent that the base under an asphalt pavement matters as much as the asphalt. A residential driveway is given as 2 to 3 inches of asphalt over 4 to 6 inches of compacted aggregate, a car park as about 3 inches over 6, and a poorly compacted base is named as the cause of premature cracking and rutting.

None of that base is computed here. The Gravel Calculator owns it, including the compaction multiplier that is correct there and wrong on this page.

The split matters more than tidiness. A reader who took this page's no compaction rule to a base quantity would under-order the stone by about a third, which is exactly the error the gravel page exists to prevent. One page owns mass and the other owns volume, and the correction that belongs to each is the difference between them.

The same boundary rules out the rest. This page does not design a pavement section, select a mix or a binder grade, specify an aggregate gradation, perform a compaction test or measure a Rice value for you, and it computes no milling, removal, wedge or taper quantity.

What Is an Asphalt Calculation

An asphalt calculation turns an area and a depth into tons, and the two hard parts are what depth to use and what density to multiply by.

The depth is the compacted one, the finished surface after rolling. The paver spreads a thicker lift to get there, and that placed depth is a machine setting rather than a quantity. Entering it produces a tonnage the job does not need.

The density is not a property of asphalt. Published guidance derives it from the mixture's maximum specific gravity multiplied by 62.4 to give a solid density, and then by the percent compaction the specification calls for. Two projects with the same mix and different specified compaction have different acceptable densities and different tonnages.

Then the answer has to be an order. Asphalt is quoted and delivered by the ton, so the cubic yard figure on this page is there for checking a quote rather than for placing one, and it is reported as compacted because that is the only state this page computes.

And underneath all of it sits a base course that this page does not touch, because the correction that belongs to a base is the opposite of the one that belongs to asphalt.

Key Facts

  • A roller changes the volume of asphalt and not its mass, so tonnage remains constant regardless of compaction, which is why suppliers and contractors quote it.
  • No compaction factor belongs on a tonnage figure. The compaction figure on this subject is a thickness: the paver spreads a lift 10 to 15 percent thicker than the finished depth.
  • Published Asphalt Institute guidance gives the maximum unit weight as the mixture's Rice value multiplied by 62.4 pounds per cubic foot.
  • The acceptable unit weight is that solid density multiplied by the specified percent compaction, so a typical Rice value of 2.500 gives 156.0 solid, 148.2 at 95 percent compaction and 145.1 at 93 percent.
  • The 145 and the 148 that circulate as rival standard densities are therefore one mix at two specified compactions rather than two properties of asphalt.
  • Specifying 93 percent compaction is the same statement as allowing a maximum of 7 percent air voids in the compacted mat.
  • The Asphalt Institute's own quantity example uses 148 pounds per cubic foot: 83.3 cubic feet times 148 is 12,328 pounds, which is 6.1 tons.
  • The density on this page comes from one of three sources and the result names which: a planning band for the mix type, a figure from a job mix formula, or a Rice value at a specified compaction.
  • Published density bands by mix: hot mix 145 to 150, warm mix 142 to 148, dense graded 148 to 152, open graded 135 to 142 and stone matrix 140 to 145 pounds per cubic foot.
  • Published bands by course: surface courses with finer aggregate 143 to 147, binder courses with coarser aggregate 146 to 150.
  • On 1,000 square feet at 3 inches the density band alone moves the order from 17.75 tons at 142 to 18.50 tons at 148, which is 4.2 percent.
  • At 145 pounds per cubic foot a compacted cubic yard weighs 3,915 pounds, which is 1.96 tons.
  • Three cubic yard conversions circulate for that same density: 1.96 for compacted material, 1.4 for loose spread material, and 2.4 stated without a state.
  • A cubic yard weighing 2.4 tons would need a density of 178 pounds per cubic foot, which is above every published band, and following that figure over-orders by about 23 percent.
  • Published Asphalt Institute guidance gives a lift thickness of 3 to 4 times the nominal maximum aggregate size for dense graded mixes.
  • The stated reason is workability: too thin a mat does not have sufficient workability and too thick a mat may be unstable.
  • That ratio is a minimum rather than a maximum, and published conference material lists thin lifts being easier to compact as a myth, because a thicker lift lets the paver run slower, cools more slowly and gives more room to work the mix into a denser mass.
  • The ratio governs each lift rather than the total, so three inches laid as one and two on a half inch aggregate has a total inside the band and a first lift below it.
  • One ton of compacted hot mix at 145 pounds per cubic foot covers about 165 square feet at 1 inch, 83 at 2 inches, 55 at 3 and 41 at 4, and coverage halves as the thickness doubles.
  • Published waste allowances are 5 to 10 percent, and the reason given is that nobody likes running short with a hot paver waiting.
  • The square yard is the standard unit in agency specifications and paving bid documents.

Applications

  • Someone with a quote in tons per cubic yard checks it against the density and finds which of three published conversions the supplier used.
  • A contractor moving between this page and the Gravel Calculator sees why one carries a compaction multiplier and the other must not.
  • A reader with a job mix formula enters the density from it and watches the tonnage move off the planning band and onto one figure.
  • Someone told to compact to 95 percent rather than 93 finds out that the specification changed the density and therefore the tonnage.
  • A paving crew checks a thin overlay against the aggregate size and finds the lift below the published minimum.
  • A reader planning two lifts finds each one checked separately rather than the total, and each one priced as its own order.
  • Someone setting a paver reads the placed depth beside the compacted one and sees that the tonnage did not move.
  • A buyer comparing a per ton price against a per cubic yard price converts between them with the state named.

Example Calculations

Example 1. The same mix, two specifications, two tonnages

Given: 1,000 square feet at 3 inches compacted, a mix with a Rice value of 2.500.

The solid density is 2.500 times 62.4, which is 156.0 pounds per cubic foot.

At 93 percent compaction the acceptable unit weight is 145.08, and the tonnage is 1,000 times 0.25 times 145.08 divided by 2,000, or 18.14 tons.

At 95 percent it is 148.2, and the tonnage is 18.53 tons.

Result: 0.39 tons of difference on one job from a line in the specification. The mix did not change and the pavement did not change. The percent compaction did, and it is the number most calculators hide inside a 145.

Example 2. The cubic yard, three published answers

Given: the same job, and a supplier quoting by the cubic yard.

At 145 pounds per cubic foot a cubic yard holds 27 cubic feet and weighs 3,915 pounds, which is 1.96 tons compacted.

One published source gives 1.4 tons per cubic yard for loose spread material. This page reports that figure and does not reproduce it, because the two published loose relationships do not agree with each other.

One published source prints a conversion table headed as using 145 pounds per cubic foot and gives 2.4 tons per cubic yard.

Result: 2.4 tons in 27 cubic feet requires 177.8 pounds per cubic foot. The widest published band on this subject runs from 135 for open graded to 152 for dense graded, so that figure is not a state of any asphalt, and a reader following it over-orders by about 23 percent on a material that arrives hot and cannot go back.

Example 3. The lift that passes as a total and fails as a lift

Given: 3 inches of compacted pavement laid as a 1 inch surface over a 2 inch binder, on a mix with a half inch nominal maximum aggregate size.

Published guidance gives the minimum lift as 3 to 4 times the nominal maximum size, which is 1.5 to 2 inches for a half inch aggregate.

The total of 3 inches is inside that band. The 2 inch binder is inside it. The 1 inch lift is below it.

Result: the check runs on each lift, so the thin lift is named as below the published minimum and the tonnage is still computed. The published reason is workability: too thin a mat does not have sufficient workability, and a lift barely thicker than the stones in it cannot be worked into a dense mat.

A calculator checking the total alone would pass this job.

Example 4. The paver setting that is not a quantity

Given: 1,000 square feet at 3 inches compacted, 145 pounds per cubic foot, a 15 percent loose factor.

The tonnage is 1,000 times 0.25 times 145 divided by 2,000, or 18.13 tons.

The paver spreads the lift at 3 times 1.15, which is 3.45 inches.

Result: 18.13 tons and a 3.45 inch placed depth. The tonnage is the same figure with or without the loose factor, because a roller moves the same mass into less space and creates none. The coverage figure stays at the compacted 3 inches too, and never at the placed 3.45.

A calculator multiplying the tons by 1.15 would order 20.85 tons, which is 2.72 tons of asphalt that does not exist.

Example 5. Two lifts, two mixes, two orders

Given: 1,000 square feet, a 2 inch binder at 148 pounds per cubic foot and a 1.5 inch surface at 145, with 10 percent waste.

The binder is 1,000 times 0.1667 times 148 divided by 2,000, or 12.33 tons, and 13.57 to order.

The surface is 1,000 times 0.125 times 145 divided by 2,000, or 9.06 tons, and 9.97 to order.

Result: 23.54 tons to order in total, reported as 13.57 and 9.97 rather than as one figure. They are different mixes at different densities from possibly different plants, and a single total is not an order anybody can place.

Standards & References

The density derivation, the quantity example at 148 pounds per cubic foot and the lift thickness ratio of 3 to 4 times the nominal maximum aggregate size are published by the Asphalt Institute in its engineering guidance and are quoted here rather than paraphrased.

The density bands by mix type and by course come from calculator sites and trade pages rather than from association material, and they are reported as planning figures with the derivation given beside them. That is why a band returns a tonnage range on this page and a job mix figure returns a single number: a density computed from a Rice value and a specified compaction is a project figure, and a band is not.

The direction of the lift ratio, that it is a minimum rather than a maximum, comes from published conference material from a state asphalt association.

The three cubic yard conversions are reported with what each is: 1.96 reproduces from the density, 1.4 is published for loose spread material and is not reproduced here because the two published loose relationships do not reconcile, and 2.4 is impossible at the density it is printed against.

The waste allowance of 5 to 10 percent is trade guidance. It is an ordering allowance for shortage, delivery, rounding and field variation rather than a compaction allowance.

This page reports quantities and issues no pass or fail. It does not design a pavement section, select a mix, specify a binder grade, perform a compaction test or compute a target density for you, and it does not compute the aggregate base, which is the Gravel Calculator's and carries a compaction rule that is the opposite of this page's.

Units

Areas are entered and reported in square feet, square yards and square metres. A square yard is 9 square feet, and the square yard is the unit agency specifications and paving bids use, which is why it appears on every result rather than only where the selector asks for it. A 1,000 square foot job is 111.11 square yards and 92.90 square metres.

Thicknesses are in inches with millimetres alongside at 25.4. Three inches is 76.2 mm, and the 0.25 feet the equation uses is the same figure divided by twelve.

Density is in pounds per cubic foot with kilograms per cubic metre alongside at 16.0185. So 145 pounds per cubic foot is 2,322.7 kilograms per cubic metre, 148 is 2,370.7 and the 156.0 solid density is 2,498.9.

Tonnage is in US tons of 2,000 pounds with tonnes alongside at 0.90718474. So 18.13 US tons is 16.44 tonnes.

The Rice value is a specific gravity, so it is dimensionless and the same number in both systems. The 62.4 that converts it is the weight of a cubic foot of water in pounds, and this page runs that one derivation in both unit systems and converts the answer. That is why a 2.500 Rice value reads 2,498.9 kilograms per cubic metre rather than a round 2,500: the metric figure is the association's own arithmetic converted rather than a second derivation with a different constant in it.

Coverage per ton is reported in square feet per ton with square metres per tonne alongside. The per inch figure is tons per square foot per inch of depth, and its metric equivalent is kilograms per square metre per millimetre, which is the same physical quantity converted rather than recomputed.

The tack coat rate is in gallons per square yard with litres per square metre alongside, and the volume in US gallons with litres.

The percent compaction, the waste allowance, the loose thickness factor and the lift ratio are dimensionless and identical in both systems.

Nominal maximum aggregate size is given in inches in US practice and in millimetres in Superpave designations, where a 12.5 mm mix is the metric name for the half inch nominal maximum size. Those are product designations rather than conversions of each other, so the field converts the number you type and does not rename your mix.

The internal unit selector governs the fields, labels, math, on-screen result and any exported result, and it takes priority over any site-wide unit switch. Switching converts the values you entered rather than reinterpreting them.

Limitations

  • This page reports quantities and issues no pass or fail. The published figures are association guidance and trade practice rather than limits.
  • It does not design a pavement section. Total thickness comes from traffic loading, subgrade and agency methods, and this page names typical figures without choosing one.
  • It does not compute the aggregate base. That is the Gravel Calculator's, and it carries a compaction multiplier that would be wrong here.
  • It measures no Rice value. Where you enter one with a specified compaction it applies the association's derivation, and the laboratory test itself is not something a calculator can do.
  • It does not select a mix, a binder grade or an aggregate gradation.
  • It derives no loose tonnage. The two published loose relationships do not reconcile, so the cubic yard figure is compacted only and the published 1.4 tons per cubic yard is reported as published and unreproduced.
  • The density bands by mix type come from trade pages rather than association material and are planning figures, which is why a band returns a range here rather than one number.
  • The minimum lift ratio is published guidance rather than an acceptance test. A lift below the band is named and the tonnage is computed anyway.
  • It does not model milling, removal, wedges or tapers, which published guidance says to calculate separately.
  • It holds no published tack coat rate of its own and applies only a rate you bring.
  • Any cost is arithmetic on a price you entered, with no haul, mobilisation or tax in it.

Common Mistakes to Avoid

  • Adding a compaction factor to the tonnage. A roller changes volume and not mass, so the tons do not move.
  • Entering the placed depth instead of the compacted one. The paver spreads 10 to 15 percent thicker, and on a 3 inch job that is 2.72 extra tons of asphalt that does not exist.
  • Carrying the gravel rule onto asphalt. Gravel is bought by volume and needs the multiplier; asphalt is bought by mass and must not have it.
  • Treating 145 as the density of asphalt. It is a Rice value of 2.500 at 93 percent compaction, and 148 is the same mix at 95.
  • Using one density for every lift. Binder and surface courses have different mixes and different published bands.
  • Averaging a supplier density with a table figure. The job mix formula wins outright.
  • Reading a tons per cubic yard figure without its state. Compacted and loose are different numbers for the same material.
  • Using the published 2.4 tons per cubic yard. It requires 178 pounds per cubic foot, which is above every published band.
  • Checking the minimum lift against the total thickness. The ratio governs each lift, so three inches as one and two can pass as a total and fail as a lift.
  • Assuming a thin lift is easier to compact. Published guidance lists that as a myth, because a thicker lift cools more slowly and gives more room to work the mix.
  • Calling the waste allowance a compaction allowance. It covers shortage, delivery, rounding and field variation.
  • Ordering by the cubic yard. Asphalt is quoted and delivered by the ton, and the volume figure is for checking a quote.
  • Summing two lifts into one order. Different mixes from possibly different plants are different orders.
  • Entering an area in square yards on a field asking for square feet. Paving documents are normally in square yards, and the two differ by a factor of nine.

Frequently Asked Questions

How many tons of asphalt do I need?
Area in square feet times thickness in feet times density in pounds per cubic foot, divided by 2,000. A 1,000 square foot driveway at 3 inches and 145 pounds per cubic foot is 18.13 tons before waste.
Do I add a compaction factor to the tonnage?
No. A roller changes the volume and not the mass, so tonnage is constant regardless of compaction. The compaction figure on this subject is a thickness: the paver spreads the lift 10 to 15 percent thicker than the finished depth.
What is the density of asphalt?
There is no single figure. Published Asphalt Institute guidance derives it as the mixture's Rice value times 62.4 for the solid density, times the specified percent compaction. A Rice value of 2.500 gives 156.0 solid, 148.2 at 95 percent and 145.1 at 93.
Why do I see both 145 and 148 pounds per cubic foot?
Because they are the same mix at two specified compactions. A 2.500 Rice value at 93 percent is 145.1 and at 95 percent is 148.2, and 93 percent is the same statement as allowing 7 percent air voids.
How many tons in a cubic yard of asphalt?
1.96 tons compacted at 145 pounds per cubic foot. Published figures of 1.4 for loose material and 2.4 also circulate: the 1.4 is a loose figure this page reports without reproducing, and the 2.4 would need 178 pounds per cubic foot, which is above every published band.
How thick should each lift be?
Published Asphalt Institute guidance gives 3 to 4 times the nominal maximum aggregate size for dense graded mixes, so a half inch aggregate needs 1.5 to 2 inches. It is a minimum, it applies to each lift rather than the total, and the reason is workability.
How much does a ton of asphalt cover?
About 165 square feet at 1 inch, 83 at 2 inches, 55 at 3 and 41 at 4, at 145 pounds per cubic foot. Coverage halves as thickness doubles, and these are compacted figures that do not apply to the thicker loose lift the paver spreads.
How much waste should I add?
Published guidance gives 5 to 10 percent for shortage, delivery, rounding and field variation. It is not a compaction allowance, because no compaction figure belongs on the tonnage.

Frequently Used Together

Engineers often use these calculators in combination for complete project workflows:

Gravel Calculator

Square Footage Calculator

Concrete Calculator

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