Add up to four rooms or areas. You get the total in square feet, square yards, square meters and acres, and a cost if you enter a price per square foot.
How to measure square footage
Rectangle: length × width
Triangle: length × width ÷ 2
Circle: 3.1416 × radius²
Triangle: length × width ÷ 2
Circle: 3.1416 × radius²
- Measure wall to wall at floor level, in feet. Convert inches by dividing by 12 (8 in = 0.67 ft).
- Split L-shaped or irregular rooms into rectangles and measure each one.
- Add the pieces together. Subtract built-in areas you won’t cover, such as a kitchen island.
Worked example: two bedrooms
A 12 × 12 ft bedroom is 144 sq ft and a 10 × 11 ft bedroom is 110 sq ft, for a total of 254 sq ft, or 28.2 square yards.
Unit conversions
| To convert | Multiply by |
|---|---|
| Square feet → square yards | ÷ 9 |
| Square feet → square meters | × 0.0929 |
| Square meters → square feet | × 10.764 |
| Square feet → acres | ÷ 43,560 |
Frequently asked questions
Is carpet sold by the square foot or yard?
Both. Many stores quote per square foot now, but some still use square yards. Divide square feet by 9 to convert.
Do closets count in a home’s square footage?
Usually, yes, if they’re heated and finished. Garages, unfinished basements and porches normally don’t count in listed living area.
How do I measure a room with a bay window?
Measure the main rectangle, then add the bay as a separate small rectangle or trapezoid.
Written and reviewed by Dr. Deepak N. Paithankar, PhD in Civil Engineering. How we build our calculators.