Asphalt Calculator
Convert driveway area and compacted depth into tons of hot-mix asphalt at the industry-standard 145 lb per cubic foot.
Estimates are for planning. Confirm quantities against your measured site and product packaging before ordering, and follow local building codes.
How to measure for asphalt
Area first: length times width in feet, with flares and aprons figured as their own rectangles and added in. Driveways widen at the road more than they appear to, so measure the flare instead of eyeballing it.
Depth is the compacted thickness of the finished mat, and the calculator’s three options cover the normal cases. 2 inches suits an overlay on existing asphalt that’s structurally sound. 3 inches is the standard for a new residential driveway carrying cars. 4 inches is for driveways that see trucks, trailers, or RV parking. What you can’t do is thin the asphalt to save money and make it up with hope; a 1.5 inch mat over a soft base cracks in the first winter.
Under new asphalt goes a compacted gravel base, typically 6 inches for a residential driveway and more on soft soils. The calculator includes a 6 inch base figure with compaction allowance, and the gravel calculator handles it separately if your spec differs.
The formula and what it assumes
Volume in cubic feet equals area times depth in inches divided by 12, times 1.05 for waste. Tons equals that volume times 145 divided by 2,000. So a 600 sq ft driveway at 3 inches is 600 × 0.25 × 1.05 = 157.5 cubic feet, and 157.5 × 145 ÷ 2,000 = 11.42 tons.
The 145 lb per cubic foot figure is the standard density for compacted hot-mix asphalt. The Asphalt Institute’s engineering FAQ gives in-place asphalt at 142 to 148 pounds per cubic foot, so the true tonnage for your specific mix can drift a percent or two either way. Your paving contractor or plant will quote against their own mix density; this calculator gets you close enough to sanity-check the bid.
The gravel base line figures 6 inches compacted over the same area, with 15% extra for compaction: 12.78 cubic yards for that 600 sq ft drive. The formula assumes uniform depth, so a driveway being reshaped or crowned needs judgment on top of arithmetic.
Why asphalt is contractor territory
Concrete forgives a slow crew; asphalt doesn’t. Hot-mix leaves the plant around 300°F and must be spread and compacted before it cools below roughly 175°F, which on a cool day gives you well under an hour. Below that temperature the mix stops compacting and the mat ends up porous, and porous asphalt soaks up water and fails from the inside. Doing it right takes a paver or experienced rake crew, a steel-drum or plate roller, and a dump truck arriving on schedule, none of which rents sensibly for a one-driveway job.
So the practical division of labor: you handle measurement and the base math, and a paving contractor handles the mat. Expect quotes in the range of $3 to $7 per square foot installed for a standard residential driveway as of 2026, sensitive to local asphalt prices and access. Use this calculator’s tonnage to compare bids; a quote priced on 8 tons for a job that needs 11 is telling you where the contractor plans to save.
DIY still has a place at the edges. Bagged cold patch fixes potholes, crack filler handles joints, and a driveway sealer every few years slows oxidation. If you’re weighing surfaces, a concrete driveway costs more up front but suits DIY in sections, while asphalt is cheaper, faster, and all-or-nothing.
Timing and prep notes
Pave in warm weather; most contractors won’t lay residential hot-mix below about 50°F, and the mat behaves better in late spring through early fall. Keep cars off for 3 to 5 days, longer in heat, and wait a season before the first sealcoat so the surface oils oxidize. The base does the structural work, so if your contractor’s prep step looks fast and casual, that’s the part of the bid to question.
Frequently asked questions
How many tons of asphalt do I need?
Multiply area in square feet by compacted depth in feet, then by 145 pounds per cubic foot, and divide by 2,000. A 600 sq ft driveway at 3 inches is 600 × 0.25 × 145 ÷ 2,000 = 10.9 tons, or about 11.4 tons with the calculator's 5% allowance. As a quick check, 100 square feet at 2 inches is roughly 1.2 tons.
How thick should an asphalt driveway be?
3 inches compacted is the common residential spec over a sound 6 inch gravel base. An overlay on existing asphalt can be 2 inches, and driveways carrying trucks, RVs, or trailers should go to 4 inches. Note that depth means compacted depth: pavers lay the mix thicker and roll it down, which is their problem to solve, not yours.
Why 145 pounds per cubic foot?
It's the industry's standard working density for compacted hot-mix. The Asphalt Institute puts in-place asphalt at 142 to 148 pounds per cubic foot depending on the mix, so 145 is the middle of the range. Plants sell by the ton, which is why every asphalt estimate converts volume to weight.
Can I pave a driveway with cold patch?
No. Bagged cold patch is a repair product for potholes and utility cuts; it never reaches hot-mix density and stays semi-flexible indefinitely. It's great for filling a hole until a proper repair, and wrong for any area larger than a couple of square feet. New surfaces need hot-mix laid and compacted at temperature.