Free Square Footage Calculator
Measure a room, a yard or a whole floor plan. Add as many areas as you need, in any unit, and get the total in square feet, square meters and square yards, plus an optional material cost.
Total area
How to use the square footage calculator
- Pick a shape for the first area and enter its measurements. Rectangles need length and width, circles need a diameter, triangles need a base and height.
- Choose the unit you measured in. Every area can use a different unit.
- Click "Add area" for each extra room or section. For an L-shaped room, split it into two rectangles.
- Optionally enter a price per square foot and a waste percentage to estimate flooring, sod or paving costs.
Measuring tips
Square footage is length times width for a rectangle. For anything more complicated, break the space into simple shapes, measure each one, and add them up. That is what the rows in this calculator are for. Measure wall to wall at floor level and round to the nearest inch; small errors multiply when you square them.
When buying materials, always add a waste allowance. Flooring installers typically add 5–10% for straight layouts and 15% or more for diagonal or herringbone patterns, since cuts at the walls cannot be reused. Tile, sod and pavers follow similar rules. It is much cheaper to have a few extra pieces than to make a second trip and find the batch or dye lot has changed.
For real estate, the square footage of a home usually means finished, heated living space measured from the exterior walls, and it excludes garages, unfinished basements and open porches. Measurement standards vary by region and appraiser, so do not be surprised if your own tape-measure total differs from a listing.
Need a different tool? Suggest it here — we read every message.
Frequently asked questions
How do I calculate square footage of an irregular room?
Split it into rectangles, triangles and circles, add each as its own row, and the calculator totals them. For a cut-out (like a closet you do not want to count), measure it separately and subtract it.
How many square feet are in a square meter?
One square meter is about 10.764 square feet. One square yard is exactly 9 square feet.
How much extra flooring should I buy?
Add about 10% for most rooms, and 15% or more for diagonal layouts or rooms with many corners.
How do I measure in inches?
Choose "in" as the unit. The calculator converts to square feet automatically (144 square inches = 1 square foot).