Hot Mix Asphalt Calculator: HMA Tons, Density & Placement Spec
Hot mix asphalt compacts to 145 lb/ft³ typical, ships at 290–325°F, and places at 250–275°F. The calculator below sizes your HMA order in tons or metric tonnes, with the engineer's reference table for density, mix temp, and Marshall stability.
This page answers:
- How many tons of HMA / hot mix asphalt for my project?
- What's the right density and placement temperature?
- What does "Marshall stability" or "Superpave" mean on the spec sheet?
HMA calculator
Hot mix asphalt at-a-glance specifications
Higher for binder-modified mixes. Lower limit prevents premature aging.
At the screed. Below 225°F compaction fails — porosity locks in.
ASTM D6927. Drops to 1,000-1,500 for residential / low traffic mixes.
Target 4% per Superpave. >7% = porous; <3% = bleeds in heat.
Of total mix weight. Surface mixes use 5.5-6.5%, base mixes 4.5-5.5%.
How to calculate hot mix asphalt tonnage (5 steps)
Tons = Length × Width × Depth(ft) × 145 ÷ 2,000 × (1 + Waste%)
= ft³ × 0.0725 × waste [shortcut at 145 lb/ft³]
≈ SY × thickness (in) × 0.054 [DOT yield shortcut]The five-step procedure used by quality contractors and state DOTs:
- Area — Length × Width in feet = SF (or SY = SF ÷ 9).
- Thickness — convert inches to feet (in ÷ 12).
- Volume — SF × thickness (ft) = ft³.
- Weight — ft³ × 145 lb/ft³ (or use mix-specific density from the HMA reference table below).
- Tons — lb ÷ 2,000 + 5–10% waste.
For shape-specific area formulas (circles, L-shapes, road segments) and the metric version, see the how to calculate asphalt tonnage guide.
Worked example — 1,200 sq ft driveway at 3 in compacted depth:
- Volume = 1,200 × 0.25 = 300 ft³
- Weight = 300 × 145 = 43,500 lb
- Tons = 43,500 ÷ 2,000 = 21.75 tons
- With 5% waste = ~22.8 tons ordered
| Mix Type | NMAS | Use Layer | Lift Thickness | Density |
|---|---|---|---|---|
| SP 9.5 / 12.5 surface | 3/8" – 1/2" | Wearing course | 1.25–1.75" | 147–149 lb/ft³ |
| SP 19 binder | 3/4" | Binder / base | 2–3" | 145–147 lb/ft³ |
| SP 25 / 37.5 base | 1" – 1.5" | Base course | 3–4.5" | 140–145 lb/ft³ |
| OGFC (porous) | 3/8" | Wearing (drains) | 1.25" | 112–120 lb/ft³ |
| SMA | 1/2" | High-traffic wear | 1.5–2" | 149–152 lb/ft³ |
| Cold Patch | 3/8" | Pothole repair | varies | 110–125 lb/ft³ |
NMAS = Nominal Maximum Aggregate Size. SP = Superpave (per AASHTO M 323). SMA = Stone Matrix Asphalt. OGFC = Open-Graded Friction Course. Mix designations vary by state DOT — confirm with your supplier ticket.
Why placement temperature is non-negotiable
HMA depends on heat for compaction. Once mat temperature drops below 225°F, the binder stiffens and the rollers can no longer close air voids. The result is permanent porosity — water infiltrates, freeze-thaw cycles split the mix, and you get raveling within 2-3 years.
- Plant temp: 290-325°F when loaded into the haul truck
- Truck cooling rate: 1°F per minute typical (covered with insulated tarp)
- Maximum haul time: ~60 minutes; longer needs a transfer device or warm storage
- Mat temp at screed: 250-275°F minimum
- Compaction window: until 175°F for static rollers, 200°F for vibratory
This is why winter paving (ambient <50°F) is risky — heat loss accelerates and the compaction window shrinks to minutes. Most state DOTs prohibit HMA placement below 40°F ambient.
Superpave vs Marshall: which spec applies?
Most U.S. state DOTs migrated to Superpave volumetric design in the 1990s-2000s. Marshall stability (ASTM D6927) is still referenced in:
- Older municipal specifications and small-town public works contracts
- Some private commercial paving (parking lots, storage yards)
- Air Force / FAA airfield mixes (uses 75-blow Marshall)
- Many Caribbean, Latin American, and Asian markets
If you see a Superpave designation (PG 64-22, SP 12.5), the mix design is volumetric. If you see Marshall stability + flow, it's the older empirical method. Both produce serviceable HMA — just different test methods.
The FAQ below answers the questions that come up when you're ordering HMA from a plant for the first time.
Hot mix asphalt FAQ
What is hot mix asphalt (HMA)?
HMA is aggregate (stone, sand, mineral filler) coated with hot petroleum-based asphalt binder, mixed at 300-325°F at the plant and placed at 250-275°F. It compacts to 145 lb/ft³ typical density and forms the dominant pavement material in U.S. road and driveway construction.
What's the placement temperature for HMA?
Mat temperature at the screed should be 250-275°F. Mix arrives from the plant at 290-325°F and cools en route. Below 225°F mat temp, compaction fails. State DOTs typically prohibit placement below 40°F ambient.
What's the density of HMA?
Standard compacted density is 145 lb/ft³ (NAPA average). Range is 140-150 depending on aggregate gradation and binder content. SMA and high-stability mixes hit 149-152 lb/ft³; OGFC and porous mixes drop to 112-120 lb/ft³.
How many tons of HMA per cubic yard?
1.96 short tons per cubic yard at 145 lb/ft³ compacted. Use 1.95-2.05 tons/CY as a working range. Loose pre-compaction volume runs 15-20% higher — that's why suppliers price by weight, not volume.
What's Marshall stability?
Marshall stability (ASTM D6927) measures HMA resistance to deformation under load. Heavy traffic surface mix needs 1,800+ lb stability with 13-20 flow units. Lower-traffic mixes meet 1,000-1,500 lb. Most state DOTs now use Superpave instead, but Marshall still appears on residential and small commercial plans.
Hot mix vs cold mix: when do I use each?
Hot mix is the primary structural material — driveways, lots, roads. Cold mix (cold patch) is a temporary winter pothole repair: stays flexible at 0°F but doesn't bond as a structural material. Use cold patch for emergency repairs only; replace with HMA when weather allows.
What's "air voids" and why does 4% matter?
Air voids are the percentage of empty space in the compacted mix. Superpave targets 4% (range 3-5%). Above 7%, water infiltrates and accelerates failure. Below 3%, the mix bleeds binder in summer heat and ruts under truck loads. Density and air voids are inversely related.