Knowing the exact size of a room helps you buy the right amount of flooring or paint, check a listing, plan furniture, or compare quotes. Most rooms are simple rectangles, but many have a closet, a bay window or an L-shaped corner. This room square footage calculator handles all of these: measure each part, add it to the total, and get the full floor area in square feet, square metres and square yards.
How to measure a room
- Clear the edges so you can run a tape measure along the floor from wall to wall.
- Measure the length of the longest wall, corner to corner, at floor level.
- Measure the width along the wall that meets it.
- Note any extras: closets, alcoves, bay windows and doorways that the flooring will run into.
- Enter the main room, tap Add to total, then measure and add each extra in the same way.
Measure to the face of the wall, not to the edge of the baseboard. Baseboards usually sit on top of the flooring, so the floor runs underneath them.
Rectangular rooms
For a standard rectangular room, multiply length by width. A bedroom that is 11 ft by 14 ft has a floor area of 11 × 14 = 154 sq ft. If the measurements are not whole feet, use the Feet + inches unit: 11 ft 4 in by 13 ft 9 in is 11.33 × 13.75 = 155.83 sq ft.
L-shaped rooms
Split an L-shaped room into two rectangles, A and B, so that they don’t overlap. Measure each one, then add the areas. It does not matter which way you split the L, as long as every part of the floor is counted exactly once.
Closets, alcoves and bay windows
Treat each one as its own small shape. A walk-in closet is usually a rectangle; a bay window is usually a trapezoid, with the wider side against the room. Add each piece to the total. If something takes floor space away and the flooring will not go under it, such as a fitted kitchen island, add it with Subtract ticked.
Worked example: bedroom with a closet
- Bedroom: 12 ft 4 in × 11 ft 8 in = 12.333 × 11.667 = 143.89 sq ft.
- Closet: 6 ft × 2 ft = 12 sq ft.
- Total floor area: 143.89 + 12 = 155.89 sq ft (14.48 m²).
- For carpet with 10% waste you would plan for about 171.5 sq ft, or 19.05 sq yd.
Typical room sizes
Room sizes vary a lot from home to home, but these common dimensions are a useful reference when you are checking your own numbers or planning a remodel.
| Room size | Square feet | Square metres | Typical use |
|---|---|---|---|
| 10 × 10 ft | 100 | 9.3 | Small bedroom, home office |
| 10 × 12 ft | 120 | 11.1 | Bedroom, nursery |
| 11 × 12 ft | 132 | 12.3 | Bedroom |
| 12 × 12 ft | 144 | 13.4 | Bedroom, dining room |
| 12 × 14 ft | 168 | 15.6 | Large bedroom, kitchen |
| 12 × 15 ft | 180 | 16.7 | Living room, primary bedroom |
| 12 × 16 ft | 192 | 17.8 | Family room, primary bedroom |
| 13 × 15 ft | 195 | 18.1 | Primary bedroom |
| 14 × 16 ft | 224 | 20.8 | Living room |
| 15 × 20 ft | 300 | 27.9 | Large living room |
| 16 × 20 ft | 320 | 29.7 | Great room, open-plan kitchen |
| 20 × 20 ft | 400 | 37.2 | Two-car garage |
Which rooms count toward a home’s square footage?
When you measure for flooring or paint, every room counts. When a home is listed for sale or appraised, the reported figure is usually the finished, heated living area. In the US, that typically excludes garages, unfinished basements, porches and spaces with very low ceilings. If you need the official figure for the whole house, use the house square footage calculator and read our guide to measuring a house.
Frequently asked questions
How many square feet is a 10×12 room?
A 10 × 12 foot room is 120 square feet, or about 11.15 square metres.
How big is an average bedroom?
Secondary bedrooms in US homes are often between 10 × 10 ft and 12 × 12 ft, which is 100 to 144 sq ft. Primary bedrooms are commonly 12 × 15 ft to 14 × 16 ft, or roughly 180 to 225 sq ft. Your own rooms may be larger or smaller.
Should I include the closet in a room’s square footage?
For flooring, yes, if the flooring continues into the closet. For a listing or appraisal, closets inside the finished living area are part of the home’s total square footage.
How do I measure a room with angled walls?
Split the room into a rectangle plus one or more triangles or trapezoids. Measure each piece, add them to the total, and the calculator will add them up for you.
Do I measure to the wall or to the baseboard?
Measure to the wall. Baseboards normally sit on top of the finished floor, so the floor extends under them.
Does a room’s square footage include the walls?
No. Room square footage is floor area only. To find the area of the walls for painting, multiply each wall’s width by the ceiling height and subtract doors and windows.
Can I measure a room in metres?
Yes. Choose Metres in the “Measure in” box. You will still see the result in square feet, as well as square metres, square yards and the other units.