Asphalt calculator: tons, coverage and compacted thickness

How do you calculate asphalt tonnage?

Area in square feet, multiplied by thickness in feet, multiplied by density in pounds per cubic foot, divided by 2,000 to get US short tons.

At the standard 145 pounds per cubic foot, a cubic yard weighs 3,915 pounds, or just under two tons. That is a useful sanity check if a supplier quotes you in yards: roughly double the yardage to get tonnage.

Why compacted thickness is the number to use

This is where estimates go wrong. Asphalt is specified by its finished compacted thickness, but it is laid loose and then rolled, losing roughly 20 to 25% of its depth in the process. A 3 inch compacted surface is laid at close to 4 inches.

The important part: supplier tonnage figures already account for this. So enter your compacted thickness here, and do not add a separate compaction allowance on top. Doing both is the commonest way to over-order.

How thick should a driveway be?

Use	Asphalt	Aggregate base
Residential driveway, cars	2 - 3 in	4 - 8 in compacted
Driveway with trucks or an RV	3 - 4 in	6 - 8 in
Commercial parking, light	3 in	6 - 8 in
Commercial, heavy or truck route	4 - 6 in	8 in or more

The base matters as much as the surface. A poorly compacted base causes cracking and rutting no matter how thick the asphalt above it, so a thin surface on a good base outlasts a thick one on a bad base.

How much does a ton of asphalt cover?

Thickness	Coverage per ton
1 in	about 165 sq ft
2 in	about 80 sq ft
3 in	about 55 sq ft
4 in	about 40 sq ft

Spec Based on a compacted density of 145 lb/ft³, the industry planning figure cited by the National Asphalt Pavement Association and used by major producers. Mixes range 140 to 150 lb/ft³; ask your supplier for the density of the specific mix. Convention Waste allowances of 5 to 10% are trade practice, not a published standard.

Common questions

Is asphalt sold by the ton or the yard?

By the ton, almost universally in the United States, which is the opposite of concrete. If a quote is in cubic yards, multiply by about 1.96 to get tons at standard density. Keep the weigh tickets from the plant: they show gross, tare and net weight and are how you verify what was delivered against what you ordered.

What waste allowance should I use?

Five to ten percent for edges, spillage and thickness variation. Add three to five points more in cold weather, below about 50°F, because the material cools faster and more of it becomes unworkable before it is rolled.

Can I lay asphalt over an existing surface?

An overlay is common and usually 1.5 to 2 inches, but only if the existing base is sound. Paving over a cracked, moving surface means the cracks reappear through the new layer within a season or two.

Does temperature change the tonnage?

Not the calculation, which is based on compacted dimensions. It changes the waste: cold weather means faster cooling and more material that never gets properly compacted.