Square Footage Calculator
The starting point for almost every home project. Add rectangles, circles and triangles and get one clean total area.
How it works
- Rectangle area = length x width
- Circle area = pi x (diameter / 2)^2
- Triangle area = base x height / 2
- Total = every shape added together, shown in both square feet and square meters
Worked example
A 12 ft x 10 ft bedroom is 120 sq ft. Add a round rug area or entry circle of 10 ft diameter (78.5 sq ft) and the total is 198.5 sq ft, which is about 18.4 sq m. At $4 per sq ft for flooring material, that area would cost about $794.
Assumptions to know
- Measure to the longest points and round measurements up slightly - small over-measurement is safer than coming up short.
- This calculator measures floor area. Wall area for paint needs height too - use the paint calculator for that.
Results are planning estimates only. Always check the coverage and instructions on the actual product you buy, and measure your own space carefully before ordering. When in doubt, a little extra material is cheaper than a second trip or a stalled job.
Frequently asked questions
How do I find the square footage of an odd-shaped room?
Break it into rectangles, circles and triangles, add a shape for each piece above, and add the areas together. L-shaped rooms are just two rectangles.
How many square feet are in a 12 x 12 room?
144 square feet. Multiply the length by the width in feet and you have the area in square feet.
Does square footage include closets and hallways?
For flooring and paint materials, yes - measure and include any space that gets the material. For real-estate listings, rules differ by region and usually count only heated living space.
How do I convert square feet to square meters?
Multiply square feet by 0.0929. The unit toggle on this calculator converts everything for you, including your entered measurements.