Asphalt Density Calculator and Unit Converter
Convert asphalt density between pounds per cubic foot, kilograms per cubic metre, tonnes per cubic metre and pounds per cubic yard, pick a value from the sixteen-mix library, and apply it directly to a tonnage calculation.
Density converter
Type into any field and the rest update instantly. Defaults shown are dense-graded hot mix asphalt.
Specific gravity is numerically identical to density in g/cm³ and t/m³, so those three fields always show the same number.
Asphalt mix density library
All sixteen common paving materials, in every unit you are likely to need.
| Mix type | lb/ft³ | kg/m³ | t/m³ | lb/yd³ |
|---|---|---|---|---|
| Dense-graded HMA | 145 | 2,322.7 | 2.323 | 3,915 |
| Stone Matrix Asphalt (SMA) | 150 | 2,402.8 | 2.403 | 4,050 |
| Warm Mix Asphalt (WMA) | 143 | 2,290.7 | 2.291 | 3,861 |
| Open-Graded Friction Course | 115 | 1,841.8 | 1.842 | 3,105 |
| Porous / Permeable Asphalt | 100 | 1,601.8 | 1.602 | 2,700 |
| Cold Mix Asphalt | 140 | 2,242.6 | 2.243 | 3,780 |
| RAP Millings (recycled) | 125 | 2,002.3 | 2.002 | 3,375 |
| Dense Bituminous Macadam (DBM) | 148 | 2,370.8 | 2.371 | 3,996 |
| Bituminous Concrete (BC) | 147 | 2,354.7 | 2.355 | 3,969 |
| Bituminous Macadam (BM) | 135 | 2,162.5 | 2.163 | 3,645 |
| BBSG 0/10 (Béton Bitumineux Semi-Grenu) | 148 | 2,370.8 | 2.371 | 3,996 |
| BBME (Béton Bitumineux à Module Élevé) | 150 | 2,402.8 | 2.403 | 4,050 |
| Grave Bitume (GB3/GB4) | 149 | 2,386.8 | 2.387 | 4,023 |
| EME 2 (Enrobé à Module Élevé) | 152 | 2,434.8 | 2.435 | 4,104 |
| Hot Rolled Asphalt (HRA) | 143 | 2,290.7 | 2.291 | 3,861 |
| Bitumen binder (PG 64-22 / 60-70 pen) | 65 | 1,041.2 | 1.041 | 1,755 |
Apply a density to a project
Select your mix in the calculator below and the tonnage recalculates against the correct density.
Gmm, Gmb and %Gmm
| Term | What it measures | Test method | Typical value |
|---|---|---|---|
| Gmm — theoretical maximum specific gravity | Density with zero air voids | AASHTO T 209 | 2.45 – 2.55 |
| Gmb — bulk specific gravity | Density of a compacted specimen or core | AASHTO T 166 | 2.30 – 2.42 |
| %Gmm — relative compaction | Gmb ÷ Gmm × 100 | Calculated | 92 – 96% |
| Air voids (Va) | 100 − %Gmm | Calculated | 4 – 8% in place |
| In-place density | The number to estimate against | Nuclear gauge or core | 140 – 150 lb/ft³ |
Compaction acceptance on public work is nearly always specified as a percentage of Gmm rather than an absolute density, because Gmm varies with the mix design and the specification has to work across every approved mix. For estimating purposes, though, you want the in-place figure. The full explanation is in the asphalt density guide.
Frequently asked questions
How do I convert lb/ft³ to kg/m³?
Multiply by 16.0185. 145 lb/ft³ × 16.0185 = 2,322.7 kg/m³. Divide by 16.0185 to go the other way.
What is asphalt density in t/m³?
2.32 t/m³ for dense-graded hot mix. Simply divide the kg/m³ figure by 1,000.
What is the specific gravity of asphalt?
Compacted dense-graded hot mix has a bulk specific gravity (Gmb) of about 2.32, and a theoretical maximum specific gravity (Gmm) of about 2.45 to 2.55. Specific gravity is numerically the same as density in g/cm³ or t/m³.
How do I find the density of my specific mix?
Ask the plant for the mix design sheet. It states Gmm directly, and the target in-place density as a percentage of it. For estimating without a sheet, use the table on this page for your mix type.
What is lb/yd³ for asphalt?
3,915 lb per cubic yard for dense-graded hot mix, because a cubic yard is 27 cubic feet and 145 × 27 = 3,915.
Which density should I use for estimating?
The in-place compacted density for your mix type — 145 lb/ft³ for dense-graded hot mix. Never use Gmm (which has no air voids) or loose stockpile density.
Sources and further reading
Related calculators and guides
Density guide
The full 3,000-word reference.
Weight calculator
Density applied to a volume.
Tonnage calculator
Density applied to an area.
Mix types
What each mix is and where it goes.
Volume calculator
The other half of the equation.