How Many Square Feet Is an 18x18 Room?
Total area
324 sq ft
Eighteen feet by eighteen feet.
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.
- Length18 ft
- Width18 ft
- How many rooms or areas this size1
- Extra area to add0 sq ft
Total area324 sq ft
| One area | 324 sq ft |
|---|---|
| Times 1, plus extra | 324 sq ft |
| Square yards | 36 |
| Square meters | 30.1 |
| Perimeter of one area | 72 ft |
What else matters here
A vaulted ceiling does not change the floor. Square footage is a floor measurement, so a vault adds volume and not area. What the vault does change is the wall area, so more drywall and paint, and the cooling load, which the BTU calculator scales for ceiling height.
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 an 18x18 room?
324 square feet, which is exactly 36 square yards and 30.1 square meters.
Does a vaulted ceiling add square footage?
No. Square footage is measured at the floor, so a vault adds volume but not area. It does add wall area, paint, drywall and heating load.
The square footage calculator takes any dimensions you like and hands back the same list.
Other common sizes
15 more sizes are answered on the square footage calculator page