How to use the asphalt calculator
- Enter the length and width of the paved area, or the total area.
- Enter the compacted thickness — the thickness after rolling, not loose.
- Keep the default density of 145 lb/ft³ unless your supplier gives another value.
- Add 5–10% extra and your price per ton to estimate the material cost.
Asphalt tonnage formula
Volume (ft³) = Length (ft) × Width (ft) × Thickness (in) ÷ 12 Weight (lb) = Volume × 145 lb/ft³ US tons = Weight ÷ 2,000 Quick rule: tons ≈ square yards × inches × 110 ÷ 2,000
Worked example
A 50 × 12 ft driveway, 3 in thick:
- Volume = 50 × 12 × 0.25 = 150 ft³
- Weight = 150 × 145 = 21,750 lb = 10.9 US tons (9.9 tonnes)
- With 5% extra = 11.4 tons
- Check with the quick rule: 66.7 yd² × 3 in × 110 ÷ 2,000 = 11.0 tons ✓
Coverage per ton
| Thickness | ft² per US ton | m² per tonne |
|---|---|---|
| 1.5 in (3.8 cm) | 110 | 11.3 |
| 2 in (5 cm) | 83 | 8.6 |
| 3 in (7.5 cm) | 55 | 5.7 |
| 4 in (10 cm) | 41 | 4.3 |
Base course and surface course
Larger jobs are often paved in two layers. The base (binder) course uses a coarser mix and carries the load; the surface (top) course uses a finer mix that seals the pavement and gives a smooth finish. For example, a parking area might have 2 in of base course and 1.5 in of surface course. Run the calculator once for each layer — the mixes have slightly different densities, and suppliers price them separately.
Asphalt or concrete?
Asphalt usually costs less to install, can be driven on within a day or two and handles freeze–thaw cycles well, but needs seal-coating every few years. Concrete costs more up front and takes about a week to cure, but lasts longer with less maintenance and stays cooler in hot climates. If you are comparing, use our Concrete Slab Calculator for the concrete volume.
Asphalt driveway tips
- The base matters most. Most asphalt failures start with a soft or wet base. Excavate, compact the subgrade and lay 6–8 in of crushed stone.
- Plan drainage. Slope the surface about 2% (¼ in per foot) away from buildings.
- Pave in warm weather — hot mix needs to stay hot to compact properly.
- Seal-coat after the first year and every 2–3 years after that to protect it from water and UV.
- Compare quotes in tons and thickness, not just total price — thin asphalt looks the same on day one.
- Keep heavy vehicles off new asphalt for a few days, and avoid turning car wheels while parked, especially in hot weather.
- Recycled asphalt millings are a cheaper option for farm tracks and rural driveways; they compact well but are not as smooth.