Construction
Asphalt Calculator
Asphalt is sold by the ton — but you specify the job in feet and inches. This calculator does the conversion: length × width × thickness × density gives you the tons of hot-mix to order. Add your supplier's price-per-ton and you've got the material budget for a driveway, parking lot, or path in one shot.
How the math works
Asphalt is sold by weight, not by volume. To figure out how much you need, you compute the volume of the slab in cubic feet, then convert to tons using the density of compacted hot-mix asphalt (HMA).
- Volume (ft³) = length × width × (thickness in inches ÷ 12)
- Tons = volume × 0.0725 (≈ 145 lb/ft³ ÷ 2000 lb/ton)
A 30-ft × 12-ft × 3-inch driveway works out to 90 ft³ of asphalt, or about 6.5 tons. At a typical 2025 supplier price of $110/ton that's $720 of material — before grading, base, equipment, and labor.
Typical thicknesses and bases
| Application | Finish (HMA) | Base course |
|---|---|---|
| Residential driveway | 2-3" | 4-6" compacted gravel |
| Heavy-duty driveway (RV/dually) | 3-4" | 6-8" gravel |
| Parking lot — light commercial | 3" | 6" base |
| Parking lot — semi truck | 4-6" | 8-12" base |
| Walking path | 1.5-2" | 3-4" base |
Don't skimp on the base — a thick asphalt cap over a thin or unstable base will crack and rut within a year. Most failures aren't because the asphalt was too thin; they're because the gravel underneath wasn't properly compacted.
How to use this calculator
- Measure the actual paved area. Not the gravel base — the finished asphalt surface. If you're widening, only enter the new strip, not the existing slab.
- Pick the right finish thickness. 2 inches for light pedestrian or single-car use, 3 inches for a typical car driveway, 4+ inches for trucks or RVs.
- Get a price-per-ton. Call your local asphalt plant — pricing varies widely by region ($90-$160/ton in most US markets in 2025), and the plant will quote you a "tailgate" price (you haul) and a "delivered" price.
- Add 5-8% overage. Tons calculated here represent finished volume. Always order at least 5% extra for spillage, compaction loss, and uneven base.
- Verify minimum order. Most plants have a 1-2 ton minimum and won't deliver under 4-5 tons. For very small jobs (under 2 tons) you'll have to pick up.
Common scenarios
Single-car driveway, 12 ft × 50 ft × 3 in. 150 ft³ = 10.9 tons. At $110/ton = $1,200 material. Add base + grading + paving labor and a typical turnkey quote lands $5,500-$8,500 in most US markets.
Two-car driveway, 24 ft × 40 ft × 3 in. 240 ft³ = 17.4 tons of asphalt. Material around $1,900. Turnkey installed: $9,000-$13,500 depending on base condition and regional labor.
Small parking lot, 60 ft × 80 ft × 3 in. 1,200 ft³ = 87 tons. Material alone is roughly $9,600. This is enough volume that several truckloads will be running — plan paving day for a full crew with a paver and roller, not a hand-tamping project.