A 12 × 14 ft bedroom has 168 square feet of floor — 18.7 square yards or 15.6 square meters. With 8 ft ceilings, one door and one window, its walls add 384 square feet to paint or drywall, the ceiling another 168, and the baseboard runs 49 feet. The calculator above works out the floor, walls, ceiling and baseboard of a rectangular or L-shaped room, with closets added and columns taken away.
How the calculator works
Choose a rectangular or L-shaped room and enter its sides; add closets, bays or alcoves as extra areas and subtract columns or chases. Then enter the ceiling height, any extra wall length around bump-outs, and the doors and windows. The result shows each surface, the total, and the room's volume.
Floor
A rectangle is length × width. An L-shaped room is two rectangles: split it along the inside corner and add the parts — a 16 × 10 ft living area with a 10 × 6 ft dining nook is 160 + 60 = 220 ft². Measure wall to wall at floor level, inside the baseboard.
| Room | ft² | yd² | m² |
|---|---|---|---|
| 10 × 10 ft | 100 | 11.1 | 9.3 |
| 12 × 14 ft | 168 | 18.7 | 15.6 |
| 15 × 20 ft | 300 | 33.3 | 27.9 |
Walls and ceiling
Wall area is the perimeter times the ceiling height, less the doors and windows: 2 × (12 + 14) × 8 = 416 ft², less a 20 ft² door and a 12 ft² window is 384 ft². The ceiling is the same as the floor. For an L-shaped room the perimeter is twice the longer part plus both widths.
Common mistakes
- Measuring to the nearest foot. Inches add up: 12′ 7″ × 14′ 5″ is 181 ft², not 168.
- Forgetting closets. They get the same floor as the room.
- Deducting every opening for paint. Small windows barely change the paint you buy.
For flooring in the room, use the Flooring Calculator; for paint, the Paint Calculator; for drywall, the Drywall Calculator.