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
Three hundred and twenty four square feet, a great room, and the size at which somebody usually asks how a vaulted ceiling changes the number.
It does not change the floor. Square footage is a floor measurement, so a vault adds volume and not area, and a room with a two story ceiling is counted once. What the vault does change is everything priced off the walls: more drywall, more paint, scaffold time, a taller and more expensive window wall, and a heating and cooling load figured on volume rather than on floor area. Ask which number a quote is using, because a painter working off square footage and a painter working off wall area will not agree.
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.
Is a two story space counted twice?
No. An open two story room counts once, at its floor. Open space above a floor is not floor area under the standard measuring rules.
The square footage calculator takes any dimensions you like and hands back the same list.