Asphalt Density Calculator for Mix Weight, lb/ft³ and kg/m³
Look up compacted density for every common hot-mix asphalt type, then convert any volume to weight in pounds, US tons, or kilograms in one click.
Why Mix Density Varies 20% Between Asphalt Types
Telling a supplier ‘you need 20 tons of asphalt’ assumes a density. If the supplier uses 145 lb/ft³ and you measured for an SMA mix at 152 lb/ft³, your truck arrives 5% short.
Density depends on:
- Aggregate gradation — densely packed (SMA) vs. open-graded (porous friction course)
- Binder content — more binder = lower density (rare, since binder is the lightest component)
- Compaction effort — field density is 92-96% of theoretical maximum (Rice density)
- Recycled content — RAP introduces aged binder and varying aggregate
Use the reference tables on this page to nail down the right density before placing your order.
Asphalt Density Density Reference Table
| Mix Type | Density (lb/ft³) | Density (kg/m³) | Tons per yd³ | Air Voids % |
|---|---|---|---|---|
| Stone Matrix Asphalt (SMA) | 150-152 | 2,403-2,435 | 2.03-2.05 | 3-5 |
| Standard HMA Surface | 144-146 | 2,307-2,339 | 1.94-1.97 | 4-6 |
| Standard HMA Binder | 146-148 | 2,339-2,371 | 1.97-2.00 | 5-7 |
| Standard HMA Base | 142-145 | 2,275-2,323 | 1.92-1.96 | 6-8 |
| Polymer-Modified HMA | 146-150 | 2,339-2,403 | 1.97-2.03 | 3-5 |
| Cold-Mix Patch | 130-138 | 2,083-2,211 | 1.76-1.86 | 8-12 |
| Open-Graded Friction Course | 115-125 | 1,842-2,003 | 1.55-1.69 | 15-22 |
| Recycled Asphalt (100% RAP) | 120-130 | 1,922-2,083 | 1.62-1.76 | 8-15 |
| RAP-Virgin Blend (50/50) | 138-142 | 2,211-2,275 | 1.86-1.92 | 5-9 |
Density assumes typical Marshall mix design at 4% target air voids. Always reference the mix design report from your supplier.
| lb/ft³ | lb/yd³ | kg/m³ | g/cm³ | kg/L |
|---|---|---|---|---|
| 100 | 2,700 | 1,602 | 1.602 | 1.602 |
| 120 | 3,240 | 1,922 | 1.922 | 1.922 |
| 130 | 3,510 | 2,083 | 2.083 | 2.083 |
| 140 | 3,780 | 2,243 | 2.243 | 2.243 |
| 145 | 3,915 | 2,323 | 2.323 | 2.323 |
| 150 | 4,050 | 2,403 | 2.403 | 2.403 |
| 160 | 4,320 | 2,563 | 2.563 | 2.563 |
1 lb/ft³ = 16.018 kg/m³. Multiply lb/ft³ by 16.018 for SI conversion.
Density-to-Weight Converter
Enter project dimensions below — results update instantly. Switch units freely.
Estimates assume typical industry density and waste factors. Always verify with your supplier and local building code before purchasing material.
Volume-Density-Weight Math (Plain English)
Tons = Weightlb ÷ 2000
Two practical density measurements to know:
- Theoretical Maximum (Rice) Density (Gmm) — the densest the mix could ever be packed, with zero air voids. Lab-determined by Rice gravity test.
- Bulk Density (Gmb) — actual compacted in-place density. Always less than Rice due to air voids (typically 4-7% air voids for surface course).
Field compaction targets express bulk density as a percentage of Rice: 92-96% of Gmm at the mat field, 90-92% at joints. Below 90% the mix is under-compacted and water enters the voids; above 97% there's too little air for thermal expansion and the mat ruts.
Once the Asphalt Density Calculator result looks reasonable, cross-check the next job decision with the Asphalt Tonnage Calculator and the Asphalt Calculator. That keeps the quantity, cost, and field assumption tied together before you call a supplier.
Real-World Example Calculations
100 ft³ of standard HMA at 145 lb/ft³
Average residential pour volume converted to weight.
- Volume
- 100 ft³
- Density
- 145 lb/ft³
Takeaway: 100 ft³ ≈ 3.7 yd³ ≈ 7.25 tons. Quick mental check for any HMA project.
10 yd³ of SMA at 152 lb/ft³
Premium intersection mix (more dense than standard HMA).
- Volume
- 10 yd³ (270 ft³)
- Density
- 152 lb/ft³
Takeaway: SMA density is ~5% higher than standard HMA — order tonnage accordingly.
5 yd³ of recycled (RAP) at 125 lb/ft³
RAP base course for a country driveway.
- Volume
- 5 yd³ (135 ft³)
- Density
- 125 lb/ft³
Takeaway: RAP is 14% lighter per cubic yard than virgin HMA — you get more volume per ton.
Frequently Asked Questions
What is the density of asphalt?
Standard hot-mix asphalt is 145 lb/ft³ (2,323 kg/m³) at typical 4% air voids. The range across mix types is 115 (open-graded) to 152 (SMA) lb/ft³. Always confirm density with your supplier's mix design ticket.
How many pounds in a cubic foot of asphalt?
For standard hot-mix: 145 pounds per cubic foot. For SMA: 150-152 lb/ft³. For RAP-blended mixes: 130-140 lb/ft³. The range exists because aggregate gradation and binder content vary.
What is the difference between bulk density and theoretical maximum density?
Theoretical Maximum (Rice) density is the densest the mix could ever be (zero air voids). Bulk density is the actual placed density, always lower because of air voids. Field compaction targets 92-96% of Rice density at the mat field.
How do I convert asphalt density from lb/ft³ to kg/m³?
Multiply by 16.018. Example: 145 lb/ft³ × 16.018 = 2,323 kg/m³. Going the other way: divide kg/m³ by 16.018 for lb/ft³. The unit toggle in the calculator above handles this automatically.
Does asphalt density change with temperature?
Yes — loose mix at 320°F is about 5-8% less dense than after compaction and cooling. Tonnage is calculated on cooled-and-compacted density (the 145 lb/ft³ figure). Trucks haul mix at near-loose density but charge by ticket weight.
How is asphalt density measured in the field?
Three common methods: (1) Nuclear gauge — emits gamma rays and measures backscatter (most common), (2) Cores — cut a 4-in cylinder from the placed mat and weigh dry/saturated/submerged, (3) Non-nuclear gauges — use electrical impedance. Nuclear is most accurate but requires safety training.
What density should I use if I don't know the mix type?
Default to 145 lb/ft³ for any standard hot-mix asphalt. This covers 70%+ of US paving applications. If you know it's a specialty mix (SMA, polymer-modified, recycled), use the table above for the correct value.