Asphalt density chart
Every asphalt tonnage calculation is volume × density. This chart supplies the density — for hot mix, warm mix, cold patch, millings and the aggregate base underneath — then shows what that number measures and how to turn it into an order in tons.
Contents
The density chart
| Material | kg/m³ | lb/ft³ | t/m³ |
|---|---|---|---|
| Hot mix asphalt (compacted)145 lb/ft³ — the estimating standard | 2,322 | 145 | 2.32 |
| Hot mix asphalt (loose, in truck)Fluffs ~20–25% before rolling | 1,870 | 116.7 | 1.87 |
| Warm mix asphalt (compacted)Same aggregates, lower placing temp | 2,300 | 143.6 | 2.3 |
| Cold mix / cold patch (compacted)Higher voids than hot mix | 2,200 | 137.3 | 2.2 |
| Asphalt millings (loose)RAP; compacts to ~1,950 | 1,650 | 103 | 1.65 |
| Asphalt millings (compacted)Good base or rural surfacing | 1,950 | 121.7 | 1.95 |
| Asphalt binder (bitumen only)PG binder, ~5–6% of mix by weight | 1,030 | 64.3 | 1.03 |
| Dense-graded aggregate baseUnder the asphalt lifts | 2,240 | 139.8 | 2.24 |
For context, normal-weight concrete sits at 2,400 kg/m³ — about 3% denser than compacted hot mix. If you work both materials, the concrete density chart is the companion reference.
Densities compared
The spread matters commercially: a tandem truck legally hauling 14 tons carries the same weight whether it is hot mix or millings — but the millings occupy about 40% more bed volume and spread further on the ground. Density is why identical tonnages produce different-looking stockpiles.
What density actually measures
For hot mix asphalt, "density" almost always means bulk specific gravity — Gmb — the as-compacted unit weight of the mix including its air voids, measured on cores or lab specimens per ASTM D2726. For estimating, that number is 145 lb/ft³ (2,322 kg/m³) for a dense-graded mix rolled to spec: 3,915 lb per cubic yard, or 1.96 US tons. Every value in the asphalt weight chart is a restatement of a Gmb for some material and state.
What a ton of HMA is made of
By weight, hot mix is almost entirely rock. The binder is a thin, heavy glue — small by mass, decisive for behavior.
- Aggregate95%
- PG binder5%
Because aggregate dominates the mass, aggregate specific gravity dominates mix density: a mix on lightweight slag or on dense traprock can sit several percent either side of 145 lb/ft³ with identical binder content. That is why mix design sheets state the design density — and why cold mix, with its cutback or emulsified binder and higher voids, compacts to only about 137 lb/ft³ (see hot mix vs cold mix weight).
From volume to weight
Tons = Volume (ft³) × Density (lb/ft³) ÷ 2,000
- Volume
- compacted in-place volume — multiply cubic yards by 27 first (ft³)
- Density
- 145 lb/ft³ compacted hot mix; see the chart above for other states (lb/ft³)
- 2,000
- pounds per US short ton
Shortcut for standard hot mix: yd³ × 1.96 = tons. Metric: m³ × 2.32 = tonnes.
One worked line: a 20 ft × 30 ft pad at 3 in compacted is 600 × 0.25 = 150 ft³, times 145 lb/ft³ = 21,750 lb = 10.9 tons. Every asphalt takeoff reduces to that single multiplication once the volume is known.
Same volume, four different tonnages
Here is the same 10 yd³ (270 ft³) order run through the formula at four common density states. The volume never changes — only the pounds packed into each cubic foot.
The spread on that chart is 3.8 tons on a 10-yard order — enough to strand a paving crew or leave a quarter of a truckload cooling on the ground. The rule for choosing: if your volume came off drawings as a finished pavement thickness, it is a compacted volume, so use the compacted density for your mix type. If you measured a stockpile, a windrow or a heaped truck bed, that is loose material at roughly 117 lb/ft³ — about 24% more volume per ton than the pavement it will become. Mixing the two states in one calculation is the most expensive mistake in small-lot asphalt buying, because it always errs in the same direction: short.
Working backwards from a ton quote
Suppliers quote tons, so invert the formula to see the volume you will actually receive: Volume (ft³) = Tons × 2,000 ÷ Density. For compacted hot mix that collapses to a constant worth memorizing — one ton places 13.8 ft³ of finished pavement, or about half a cubic yard. A 20-ton quote is therefore 276 ft³ = 10.2 yd³ of compacted mat; at 3 inches thick it will cover about 1,100 ft². Running this check on every quote takes thirty seconds and catches both over-quoting and the occasional decimal slip before the truck rolls.
| Density state | Unit weight | Per cubic yard |
|---|---|---|
| Compacted hot mix | 145 lb/ft³ | 1.96 tons13.8 ft³ per ton |
| Compacted cold mix | 137 lb/ft³ | 1.85 tons14.6 ft³ per ton |
| Compacted millings | 122 lb/ft³ | 1.65 tons16.4 ft³ per ton |
| Loose hot mix | 117 lb/ft³ | 1.58 tons17.1 ft³ per ton |
Your takeoff says 12 yd³ of compacted hot mix; the supplier delivered and billed 25 tons. Is the invoice defensible?
- 1
Takeoff volume in cubic feet
12 × 27 = 324 ft³
- 2
Takeoff weight
324 × 145 ÷ 2,000 = 23.5 tons
- 3
Delivered volume
25 × 13.8 = 345 ft³ = 12.8 yd³
- 4
Difference
25 ÷ 23.5 = 1.064 → 6.4% over takeoff
Result: The invoice is sound — 6.4% over the geometric takeoff sits inside a normal 5–10% waste and yield allowance.
Loose vs compacted — the 25% trap
Straight off the truck, hot mix sits at roughly 117 lb/ft³ — the particles are coated and lubricated but not interlocked, and about a quarter of the volume is air. Rolling drives that to 145 lb/ft³, a 25% volume reduction. The practical consequences: a 3-inch compacted lift must be spread about 3.75 inches loose (mix compacts roughly a quarter inch per inch of loose lift); a truck bed holds 25% fewer "compacted yards" than its struck volume suggests; and any yardage figure is meaningless until someone says loose or compacted. Tonnage, by contrast, is compaction-proof — which is why the industry buys and sells by weight.
Air voids: the 92–93% target
A finished mat is never void-free. Specifications target in-place density of 92–93% of the theoretical maximum (Gmm) — that is, 7–8% air voids after rolling. Traffic densifies the mat slightly further toward the 4% design void content over the first hot seasons. The target is a compromise: too many voids and the mat is permeable; too few and the binder has nowhere to go in summer, bleeding and rutting.
Checking compaction in the field
% compaction = (field density ÷ lab max density) × 100
- field density
- core or gauge reading on the finished mat (Gmb) (lb/ft³)
- lab max density
- theoretical maximum for the mix (Gmm), zero voids (lb/ft³)
Example: core at 143.5 lb/ft³ against a Gmm of 154.3 lb/ft³ → 93.0% compaction = 7.0% in-place air voids. Passes a 92% spec.
Frequently asked questions
- What is the density of compacted asphalt?
- 145 lb/ft³, equal to 2,322 kg/m³ or 1.96 US tons per cubic yard. Real mixes measured under ASTM D2726 land between 142 and 148 lb/ft³ depending on aggregate specific gravity and in-place air voids, but 145 is the estimating standard the industry quotes and plants assume.
- What is the density of loose asphalt?
- About 117 lb/ft³ in the truck bed — roughly 25% fluffier than the same material after rolling. A cubic yard of loose mix therefore weighs about 1.58 tons versus 1.96 compacted. Use loose density only for truck volume checks, never for tonnage takeoffs.
- How much does a cubic yard of asphalt weigh?
- Compacted in place: 145 × 27 = 3,915 lb, call it 1.96 tons — just under 2 tons per yard, which is the shorthand most estimators carry. Loose in a truck the same yard of volume holds only about 3,160 lb, which is why truck beds are measured in tons hauled, not yards.
- How many cubic yards is a ton of asphalt?
- About 0.51 yd³ compacted — the reciprocal of 1.96 tons per yard. In cubic feet, one ton compacts into 13.8 ft³. Loose in the truck, the same ton occupies roughly 17 ft³, which is why delivered loads look larger than the pavement they become.
- What density should I use to convert asphalt volume to tons?
- 145 lb/ft³ for compacted hot mix — the value behind every takeoff on this site, giving 1.96 tons per cubic yard. Use it whenever your volume is a designed pavement thickness. Only switch constants if you are pricing millings, cold mix, or loose material by the truckload.
- Why does the same volume of asphalt weigh different amounts?
- Because density is a state, not a property of the black stuff itself. Compacted hot mix packs to about 145 lb/ft³; the same mix loose in a truck bed runs near 117 lb/ft³, and recycled millings fall in between. Ten cubic yards therefore spans roughly 15.8 to 19.6 tons depending on state.
- How do I check a ton quote against my volume takeoff?
- Convert the quote to volume: tons × 13.8 gives compacted cubic feet, then ÷ 27 for yards. If the supplier quotes 25 tons and your takeoff says 12 yd³ (23.5 tons), the quote carries about 6% extra — a reasonable waste allowance, not an error.
- How heavy are asphalt millings?
- Loose millings run about 1,650 kg/m³ (103 lb/ft³) and compact to roughly 1,950 kg/m³ (122 lb/ft³). A tandem load of millings therefore spreads noticeably further than the same tonnage of new hot mix. Compacted millings make a serviceable base or rural wearing surface at a fraction of hot mix cost.
- What is Gmb versus Gmm?
- Gmb is the bulk specific gravity of the compacted mix — its density including air voids, measured per ASTM D2726. Gmm is the theoretical maximum specific gravity with zero voids. Their ratio is percent compaction: field cores at 92–93% of Gmm mean 7–8% air voids in place.
- Why does asphalt compaction matter so much?
- Air voids control durability. Above about 8% voids the mat becomes permeable, letting water and air age the binder and strip the aggregate; industry studies show each 1% of extra voids costs roughly 10% of pavement life. Compaction is the cheapest life-extension money buys — it is just roller passes.
- How is asphalt density measured in the field?
- Two ways: cores cut from the mat and weighed per ASTM D2726 (the referee method), or nuclear/non-nuclear gauges that read density in seconds for rolling control. Specs typically require 92–93% of Gmm on the mat and slightly less at unconfined joints, verified per lot.
- Does temperature affect asphalt density?
- It affects achievable density. Hot mix must be compacted while the binder is fluid — mat temperatures roughly 175–275°F depending on the roller pass. Below cessation temperature (~175°F) further rolling does nothing, which is why cold weather, thin lifts and long hauls all show up as low density and early failures.
- Why do plants sell by weight instead of volume?
- Because weight is invariant and volume is not. The same ton occupies about 17 ft³ loose in the truck and 13.8 ft³ after compaction. Scales at the plant read weight to the pound; nobody can measure a fluffed truck bed to 5%. Every ticket, price and takeoff therefore runs in tons or tonnes.
Related guides and tools
Sources & references
- [1]ASTM D2726: Bulk Specific Gravity of Compacted Asphalt Mixtures — ASTM International, 2021
- [2]MS-2: Asphalt Mix Design Methods, 7th ed. — Asphalt Institute, 2014
- [3]MS-4: The Asphalt Handbook, 7th ed. — Asphalt Institute, 2007
- [4]AASHTO M 323: Superpave Volumetric Mix Design — AASHTO, 2022