Asphalt calculator
Enter the size of the driveway or path and its compacted asphalt thickness. You'll get the volume and the tons of hot-mix asphalt (HMA) to order, plus a cost if you add a price per ton. The defaults are a 12 × 40 ft driveway, 3 in thick, at 147 lb/ft³ (110 lb per square yard per inch).
How the calculator works
- Area: length × width, or the area you enter.
- Volume: area × compacted thickness (inches ÷ 12), plus your waste allowance. Cubic yards = cubic feet ÷ 27.
- Weight: cubic feet × density in lb/ft³ ÷ 2,000 = US tons. One square yard 1 in thick is 0.75 ft³, so 147 lb/ft³ is about 110 lb per square yard per inch, the planning figure used in the Penn State/PennDOT asphalt field training handout.
- Cost: tons × your price per ton.
That handout gives typical compacted mixes as 108–120 lb per square yard per inch, or 144–160 lb/ft³, depending on the aggregate, asphalt content and compaction, and says to check the project's mix design for the real figure.
Driveway thickness and base
Asphalt pavement associations publish minimum designs for home driveways that carry cars, light trucks and the occasional delivery truck:
| Subgrade support | Full-depth asphalt | Or: asphalt over | aggregate base |
|---|---|---|---|
| Poor | 5.5 in | 3 in | 6 in |
| Fair | 4.5 in | 3 in | 4 in |
| Good | 4.5 in | 3 in | 4 in |
- Base: the Illinois Asphalt Pavement Association says some contractors use 6–8 in of compacted aggregate under 3 in of asphalt. It quotes NAPA as saying 1 in of asphalt is roughly equivalent to 3 in of aggregate base. Work out the stone with the gravel calculator (crusher run).
- Lifts: IAPA says asphalt is best placed in layers. For example, 2–3 in total can go down as two lifts of about 1-1/2 in each when compacted.
- Subgrade and drainage: remove topsoil and organic material, compact the soil, and slope the driveway to drain. The Washington Asphalt Pavement Association recommends at least a 2% slope (1/4 in per foot), compaction to at least 90% of maximum theoretical density, and hot mix rather than cold mix.
- Overlays: an overlay of an existing driveway is typically 1.5–2 in of surface mix, after weak spots, holes and large cracks are cut out and patched (CAPA).
Pouring concrete instead? Use the concrete calculator. For a gravel driveway, see the gravel calculator and how to install a gravel driveway.
Sources
Checked October 15, 2026.
- Penn State / PennDOT, Superpave field training handout (2024, PDF): 110 lb/sy/in (147 lb/ft³), typical 144–160 lb/ft³.
- Colorado Asphalt Pavement Association, Asphalt driveways tech brief (2020, PDF): minimum thickness designs, overlays.
- Illinois Asphalt Pavement Association, Driveways: full-depth vs aggregate base, NAPA's 1:3 ratio, lifts.
- Washington Asphalt Pavement Association, Residential driveways: slope, compaction, hot vs cold mix.