How Many Tons of Asphalt for a 40 by 40 Pad?

A 40 by 40 foot pad is 1,600 square feet. At 145 pounds per cubic foot that is about 19.3 tons at 2 inches, about 29.0 tons at 3 inches, and about 38.7 tons at 4 inches. Use the thickness that matches cars versus trucks. The plant ticket is the real weight.

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Square the pad, then run one formula

Forty times forty is 1,600 square feet, a square large enough to be a small lot, a shop yard, or a court. The planning density is 145 pounds per cubic foot of compacted hot mix. Tons equal length times width times inches divided by 12, times 145, divided by 2000. At 2 inches, 1,600 times 2 divided by 12 is about 266.7 cubic feet, times 145 is about 38,667 pounds, divided by 2000 is about 19.3 tons. At 3 inches, 1,600 times 0.25 is 400 cubic feet, times 145 is 58,000 pounds, divided by 2000 is 29.0 tons. At 4 inches, 1,600 times 4 divided by 12 is about 533.3 cubic feet, times 145 is about 77,333 pounds, divided by 2000 is about 38.7 tons. Each figure is a planning estimate. The plant ticket is the real weight.

Cars and trucks should not share one unspoken thickness

About 19.3 tons is the 2-inch plan, a surface thickness on a sound base for light vehicles. About 29.0 tons is 3 inches across the whole square. About 38.7 tons is 4 inches. A pad this size may park cars in one area and a truck or a dumpster at the edge. Those uses do not have to share one thickness, but if the quote uses one number it should say which plan it is. None of the three is a code requirement. The soil and the vehicles decide the section. A pretty square on soft ground will rut at any of these thicknesses if the base is mud. Stone under the pad is a separate order, often planned near 1.4 tons per cubic yard, and the quarry ticket is the real stone weight. Do not fold that stone into the 29-ton asphalt figure.

Edges, slope, and the tickets

A 40-foot square has a long edge. Extend the compacted base past the asphalt so the rim does not break, and include that extra stone in the quarry order, not in the asphalt tons. Slope the pad so water leaves. A square with no outlet becomes a pond in the middle, and a pond is not fixed by extra tons. If the job is more than one truck, add the scale tickets and compare the sum with 19.3, 29.0, or 38.7, whichever thickness you bought. Handwork is a smaller share of a pad this open, so the ticket should track the formula more closely than a tight driveway, unless the crew filled ruts you did not measure. Ask about those low spots before you call an overrun a mistake or a short load a success.

A practical sequence

Use 1,600 square feet for a true 40 by 40 pad.
Plan about 19.3 tons at 2 inches, 29.0 at 3 inches, or 38.7 at 4 inches.
Match the thickness to cars or trucks, and keep gravel on its own ticket.
Add the asphalt scale tickets and compare them with the planning estimate.

The mistake to skip

Quoting 29 tons without saying it means 3 inches, or mixing gravel into that asphalt number.

Questions people ask

Is a 40 by 40 pad the same tons as 2,000 square feet?

No. Forty by forty is 1,600 square feet, not 2,000. At 3 inches it is about 29.0 tons, while 2,000 square feet at 3 inches is about 36.3 tons. The gap is the missing 400 square feet. Measure the square you have. Do not round 40 by 40 up to an even 2,000. The plant ticket is the real weight either way.

Which of the three tonnages should I buy?

Buy the thickness the vehicles and the base require, then use the matching weight: about 19.3, 29.0, or 38.7 tons. This page does not pick a code thickness. A car court on firm ground is a different plan from a truck pad. Tell the contractor what will park there, keep stone separate, and let the plant ticket confirm the asphalt.

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