Asphalt Calculator

1. Enter the surface dimensions. Measure the length and width of the area you are paving in feet. For a driveway, measure from the road edge to the garage and from one side to the other. For irregular shapes, break the area into rectangles and add the results together.
2. Set the thickness. Residential driveways are typically 2 to 2.5 inches of asphalt on a compacted gravel base. Add a 3-inch layer if you park heavy trucks, RVs, or boats. Parking lots and commercial areas generally require 3 to 4 inches. Never use less than 2 inches for any paved surface that will see vehicle traffic.
3. Adjust the compaction factor. Hot mix asphalt is placed loose and then compacted by a roller. The default 1.3 factor means loose asphalt compacts to about 77% of its original volume. Most residential paving contractors use 1.25 to 1.35. Leave this at 1.3 unless your supplier specifies otherwise.
4. Enter price per ton. Asphalt prices vary significantly by region and season. Call local paving contractors or asphalt plants for a current quote. The calculator multiplies tons needed by the price per ton for a rough material cost estimate.

Example: a 12 ft × 50 ft driveway at 2.5 inches thick requires about 8.9 tons of asphalt. At $120 per ton for hot mix, material cost runs approximately $1,068. Add the base preparation, gravel, and labor to get the full project cost, which typically runs $3 to $7 per sq ft installed for residential driveways.

Asphalt quantities are ordered by the ton. The calculation converts surface area and thickness to cubic feet, applies the density of hot mix asphalt (approximately 145 lbs per cubic foot), then adjusts for compaction to get the final tonnage needed.

The compaction factor accounts for the difference between loose (uncompacted) hot mix and its final compacted state. Most asphalt plants sell by the ton of loose material before compaction. The actual delivered weight is what you pay for, and rolling reduces it by about 23 to 30%. A 1.3 compaction factor is a standard industry assumption for residential applications.