There is no single weight for a cubic yard of asphalt, and any site that gives you one number is guessing on your behalf. The weight comes from the mixture's bulk specific gravity: tons per cubic yard = Gmb × 0.8424. A dense-graded mix at a Gmb of 2.35 works out to 1.98 tons per cubic yard, or 146.6 pounds per cubic foot. Here is where that comes from, and where to find the Gmb for your job.
The conversion, from first principles
Specific gravity is a ratio: how much heavier the material is than the same volume of water. Water weighs about 62.4 pounds per cubic foot, so:
Tons per cubic yard = Gmb × 62.4 × 27 ÷ 2,000 = Gmb × 0.8424
27 cubic feet per cubic yard · 2,000 lb per short ton
| Gmb | lb per cubic foot | Short tons per cubic yard | Cubic yards per ton |
|---|---|---|---|
| 2.20 | 137.3 | 1.853 | 0.540 |
| 2.25 | 140.4 | 1.895 | 0.528 |
| 2.30 | 143.5 | 1.938 | 0.516 |
| 2.35 | 146.6 | 1.980 | 0.505 |
| 2.40 | 149.8 | 2.022 | 0.495 |
| 2.45 | 152.9 | 2.064 | 0.485 |
| 2.50 | 156.0 | 2.106 | 0.475 |
The spread across that table is about 12%. That is the size of the error you accept when you use somebody else's average instead of your own mix.
Where the real number lives
Two specific gravities show up on every asphalt job, and they are not interchangeable:
- Gmb — bulk specific gravity of the compacted mixture. Measured on compacted specimens or cores under AASHTO T 166 / ASTM D2726. This is the one that converts volume to weight, because it describes the material as it sits in the pavement, air voids included.
- Gmm — theoretical maximum specific gravity, the "Rice value". Measured on loose mix under AASHTO T 209 / ASTM D2041, with no air voids at all. It is the reference for compaction, not for tonnage.
In-place density is expressed as a percentage of Gmm — FHWA reports state results that way, and Caltrans' construction manual instructs inspectors to report core results as the "percentage of theoretical maximum density" using the Rice value from the day the mix was placed. That is why a paving spec says "92% of Gmm" rather than a number of pounds.
The Gmb for your job is on the mix design submittal and on the daily QC reports. Ask the plant for it before you build the estimate; it takes one email and removes the biggest unknown in the calculation.
Worked example: a 100-foot driveway
Paving 100 ft long by 24 ft wide, 2 inches compacted, with a mix whose Gmb is 2.35:
- Volume = 100 × 24 × (2 ÷ 12) = 400 cubic feet = 14.8 cubic yards
- Density = 2.35 × 62.4 = 146.6 lb/ft³
- Weight = 400 × 146.6 = 58,656 lb ÷ 2,000 = 29.3 tons
- Order with a margin: at 5% that is 30.8 tons, and asphalt is bought in truckloads, so round to the load.
The asphalt tonnage calculator runs exactly this arithmetic for your own numbers: it asks for the Gmb rather than assuming a density, and returns the tons to order, the tons per cubic yard for your mix and the square feet one ton covers at your mat thickness.
The same volume-to-weight arithmetic works for anything you have to haul or lift — the load weight estimator runs it for steel, concrete, soil and other materials from published densities, and the trench and excavation calculator gives you bank-measure volumes in cubic yards when the material is coming out of the ground rather than going down as pavement.
What actually moves the density
- The aggregate. Specific gravity of the stone drives the mix; a limestone mix and a trap rock mix are not the same weight per yard.
- The compaction achieved. Density is a percentage of Gmm, so a mat at 94% weighs about 2% more per cubic foot than the same mix at 92%.
- The mix type. Open-graded friction courses, stone matrix asphalt and dense-graded surface mixes have different air void structures by design.
- Loose versus compacted. Millings, RAP stockpiles and loose mix are a different material state entirely — a stockpile figure is not a pavement figure.
Bottom line
- Tons per cubic yard = Gmb × 0.8424. Pounds per cubic foot = Gmb × 62.4.
- A dense-graded mix at Gmb 2.35 is 146.6 lb/ft³ and 1.98 tons per cubic yard.
- Gmb converts volume to weight; Gmm (the Rice value) is the reference for compaction percentage.
- Get the Gmb from the mix design, not from an average found online — the plausible range spans about 12%.
- Estimate on compacted thickness, then add a margin and round to the truckload.