Whether you are buying flooring, comparing apartments or painting, you need the area in square feet. Here is how to measure any room. Add it up instantly with the square footage calculator.
What you need
A tape measure (a laser measure is even easier), a pencil and paper. Measure to the nearest inch and write each wall down.
Rectangular rooms
Length x width. A 12 ft x 15 ft living room is 180 sq ft. If your measurements include inches, convert them to feet first: 12 ft 6 in = 12.5 ft.
L-shaped and irregular rooms
Split the room into rectangles, measure each one, and add the results. A 10 x 12 area plus a 6 x 8 nook gives 120 + 48 = 168 sq ft.
Other shapes
- Triangle: base x height / 2
- Circle: 3.1416 x radius x radius
- Bay window: treat it as a small rectangle or trapezoid and add it
Square feet to square metres
Multiply square feet by 0.0929, or divide by 10.764. 180 sq ft = 16.7 m².
Buying materials
- Flooring: add 5% to 10% for waste, 15% for diagonal or herringbone layouts. Boxes list their coverage in sq ft.
- Paint: measure wall area (perimeter x height) minus doors and windows. A litre of paint typically covers about 9 to 11 m² (roughly 100 sq ft) per coat; check the can.
- Tile: buy extra tiles from the same batch for future repairs.
Real estate listings
Listed square footage usually measures the exterior of the home and may include walls, so your interior measurement will often be smaller. In Canada, basements are frequently listed separately from above-grade living space.