Asphalt Tonnage from Area and Thickness

Hot-mix asphalt is bought by weight and placed by volume, and this formula is the bridge. Dense-graded mixes compact to roughly 145 lb/ft³ (about 2,320 kg/m³), which is where the paving contractor's rule of thumb comes from: one ton covers about 110 ft² at 1 in thick, or roughly 55 ft² at the more usual 2 in surface lift. Density varies with aggregate, a basalt mix runs heavier than a limestone one, so a mix design sheet beats a rule of thumb whenever the quantity is large.

The trap is compacted versus loose thickness. Mix laid 2.5 in behind the screed rolls down to about 2 in, and ordering against the loose depth buys 25 % too much material that nobody will take back. A worked example: 10,000 ft² of parking lot at a 3 in compacted lift, 145 lb/ft³. Volume = 10,000 × 0.25 = 2,500 ft³, mass = 362,500 lb = 181.25 tons: call it seven truckloads of 25 tons plus change, and add a few percent for the ramp-up and the joint at the end of the day.