How Many Square Feet Is a 12x18 Room?
Total area
216 sq ft
Twelve 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.
- Length12 ft
- Width18 ft
- How many rooms or areas this size1
- Extra area to add0 sq ft
Total area216 sq ft
| One area | 216 sq ft |
|---|---|
| Times 1, plus extra | 216 sq ft |
| Square yards | 24 |
| Square meters | 20.07 |
| Perimeter of one area | 60 ft |
What else matters here
Two hundred and sixteen square feet with a 60 foot perimeter. A 15 by 15 room has almost the same area, 225 square feet, and a shorter perimeter at 60 feet flat, which is the general rule: for a fixed area the square is the cheapest shape to build and finish.
That matters because a lot of the cost of a room is linear rather than area based. Baseboard, crown, top and bottom plates, the wall framing itself, drywall taping and paint all follow the perimeter. Stretch a room long and thin and the floor stays the same size while the walls, the trim and the paint all grow. It is the same reason a long narrow house costs more per square foot than a compact one.
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 12x18 room?
216 square feet, which is exactly 24 square yards and 20.07 square meters.
Why does the perimeter matter as well as the area?
Because baseboard, crown, framing, taping and paint all follow the walls. Two rooms with the same floor area can need very different amounts of all of them.
What shape room is cheapest to build?
A square. For a given floor area it has the shortest perimeter, so it uses the least framing, drywall, trim and paint.
The square footage calculator takes any dimensions you like and hands back the same list.