ContractorHandbook

How Many Square Feet Is a 9x9 Room?

Total area

81 sq ft

Nine feet by nine 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.

  • Length9 ft
  • Width9 ft
  • How many rooms or areas this size1
  • Extra area to add0 sq ft

Total area81 sq ft

One area81 sq ft
Times 1, plus extra81 sq ft
Square yards9
Square meters7.53
Perimeter of one area36 ft

What else matters here

Eighty one square feet, and exactly nine square yards. That is not a coincidence, it is the definition: a square yard is three feet by three feet, so a nine foot square is three yards by three yards.

It matters because carpet is still quoted by the square yard through much of the country, and the conversion is the single most common place a flooring quote goes wrong. Divide square feet by nine, never by three. A 1,200 square foot house is 133 square yards of carpet, not 400, and a quote that reads low by a factor of three is usually this mistake rather than a bargain.

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 9x9 room?

81 square feet, which is exactly 9 square yards and 7.53 square meters.

How do you convert square feet to square yards?

Divide by nine. A square yard is three feet by three feet, so it contains nine square feet, not three.

Why is carpet sold by the square yard?

Historic trade practice. Broadloom carpet came in yard based widths and the industry kept the unit, so many quotes still arrive in square yards while the room is measured in feet.

Different numbers?

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

Other common sizes