ContractorHandbook

How Many Square Feet Is a 30x40 Shop?

Total area

1,200 sq ft

Thirty feet by forty feet.

length x widthextralength, ftwidtharea x how many, plus anything odd shaped, in feet, yards and meters
Every material calculator on the site starts here, which is why this one also gives square yards and square meters. Odd shapes get broken into rectangles and added on, because a rectangle is the only shape a tape measure is honest about.

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
  • Width40 ft
  • How many rooms or areas this size1
  • Extra area to add0 sq ft

Total area1,200 sq ft

One area1,200 sq ft
Times 1, plus extra1,200 sq ft
Square yards133.33
Square meters111.48
Perimeter of one area140 ft

What else matters here

Twelve hundred square feet. Thirty by forty is the default pole barn and metal building size, big enough for three vehicle bays or two bays and a real shop.

If the number is going on a listing rather than a permit, the standard that governs it is ANSI Z765, which is what appraisers and most multiple listing services use. It measures to the outside of the exterior walls, counts only finished and conditioned space with a ceiling of at least 7 feet, and reports below grade space separately. A number produced any other way is not wrong so much as not comparable, which is the whole point of having a standard.

What this calculator assumes

  • Length times width, times how many areas are that size. For an L shaped room, split it into two rectangles and run this twice.
  • Square yards are square feet divided by nine, which is how carpet is still quoted in much of the country.

Questions people ask

How many square feet is a 30x40 building?

1,200 square feet, which is 133.33 square yards and 111.48 square meters.

How is house square footage officially measured?

Most appraisers and listing services use ANSI Z765: measured to the outside of the exterior walls, finished and conditioned space only, with at least a 7 foot ceiling.

What can you fit in a 30x40 shop?

Three vehicle bays, or two bays plus a workshop area. It is the most common size for a pole barn or metal building on a residential lot.

Different numbers?

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

Other common sizes