ContractorHandbook

How Much Asphalt for a 20x30 Parking Pad?

Asphalt needed

10.88 tons

600 square feet at 3 inches of compacted hot mix, at 145 pounds per cubic foot.

It does not stop at a number.

When the figures look right, the asphalt material list downloads as a real PDF with your business details on it, built inside your own browser. Nothing you type is uploaded anywhere.

length, ftcompacted, inwidth, ftvolume x 145 lb per cu ft / 2,000 = tons
Asphalt is ordered by the ton, not the yard, so the volume has to go through a density before it means anything. The thickness here is the compacted mat, which is what the spec calls for and what the plant is paid on.

How that number is worked out

These are the figures this page was built with and every line the calculator produces from them. Change anything above and all of it moves.

  • Length30 ft
  • Width20 ft
  • Compacted thickness3 in
  • Density145 lb per cu ft

Asphalt needed10.88 tons

Area600 sq ft
Compacted volume150 cu ft
Weight21,750 lb
Tons10.88order to the next quarter ton
Order11 tons
Base stone at 4 in, tons10

The material list this produces

Hot mix asphalt, tons11
Crushed base stone, tons10
Tack coat, gallons2

Compacted thickness compared

Thickness is the one number that moves the tonnage in a straight line. Two inches is a light residential overlay, six is commercial.

Compacted thicknessAsphalt neededBase stone at 4 in, tons
2 in7.25 tons10
3 in10.88 tons10
4 in14.5 tons10
6 in21.75 tons10

What else matters here

Six hundred square feet at three inches is 10.88 tons, the same as a 12 by 50 driveway. Area is area: the shape changes the paving, not the tonnage.

A pad does change the base though. A parking area takes standing load in the same spots every day rather than rolling load spread along a strip, so the base under a pad wants the same or more depth than under a driveway, compacted just as carefully.

If trucks or trailers will use it, three inches is light. Four inches over six inches of base is the usual step up, and it is much cheaper to add it now than to overlay a cracked pad later.

What this calculator assumes

  • Hot mix asphalt runs about 145 lb per compacted cubic foot, which is roughly 2 tons per cubic yard. Mixes vary, so ask your plant for theirs.
  • This is compacted thickness. Laid loose it is about 25 percent thicker before rolling.
  • A residential driveway is usually 2 to 3 inches over a 4 to 6 inch compacted base. Skimping on the base is what cracks a driveway, not the asphalt.

Questions people ask

How many tons of asphalt for a 20x30 pad?

10.88 tons at 3 inches compacted, ordered as 11.

Is 3 inches enough for a parking pad?

For cars, yes, over a properly compacted base. For trucks, trailers or an RV, step up to 4 inches over 6 inches of base.

Why is asphalt sold by the ton?

Because the plant loads it by weight. Hot mix runs about 145 pounds per compacted cubic foot, roughly 2 tons a cubic yard, so the calculator converts your area and thickness to volume and then to weight. Ask your plant for their density if you want it exact.

Different numbers?

The asphalt calculator takes any dimensions you like and hands back the same list.

Other common sizes