Square footage calculator: rooms, floors and odd shapes
Measure each rectangle, type it in feet and inches if you like, and add the areas together. Odd-shaped rooms are just a few rectangles added up.
- Feet and inches
- Rectangles, triangles, circles
- Sq yd and sq m
Measure wall to wall at floor level. For an L-shaped or odd room, split it into rectangles and use Add another area for each one.
Do the job
How it works
Area = length × width, in square feet.
Triangle = base × height ÷ 2. Circle = 3.1416 × diameter² ÷ 4.
Several areas are added together. Save each rectangle with Add another area.
Square yards = square feet ÷ 9. Square meters = square feet × 0.0929.
10% extra is shown because flooring and tile need extra for cuts.
About this tool
Who it's for
For anyone pricing flooring, carpet, paint or a contractor quote that is charged by the square foot.
Example
You enterA 12 ft 6 in by 10 ft bedroom
You get125 sq ft, or about 13.9 square yards.
What's different
- Type 12 6 or 12' 6" and it reads feet and inches.
- Adds up several rooms or parts of an L-shaped room.
- Shows square yards for carpet and square meters too.
Gotchas and tips
- Measure at the floor; walls lean and baseboards stick out.
- Closets count if the flooring goes in them.
- Round your measurements up to the next inch, not down.
Privacy: Runs entirely in your browser. Nothing you type is sent to us.
Built and maintained by the GrabTheHammer team. Updated November 2026. Spot a problem? Tell us.
Common room sizes
Typical sizes to sanity-check your numbers. Real rooms vary, so measure yours.
| Room | Size | Sq ft | Sq yd |
|---|---|---|---|
| Small bedroom | 10 x 10 ft | 100 | 11.1 |
| Main bedroom | 14 x 16 ft | 224 | 24.9 |
| Living room | 16 x 20 ft | 320 | 35.6 |
| Kitchen | 10 x 12 ft | 120 | 13.3 |
| Bathroom | 5 x 8 ft | 40 | 4.4 |
| One-car garage | 12 x 22 ft | 264 | 29.3 |
Measuring tips that save a second trip
- Write each measurement down as you take it, with a quick sketch of the room.
- Measure each wall twice. Older rooms are rarely square, so use the longer number.
- For a doorway or alcove that gets the same flooring, measure it as its own small area and add it.
- Stairs: multiply tread depth by width, add the riser if it gets covered, then times the number of steps.
Square footage questions
How do I measure an L-shaped room?
Split it into two rectangles that don't overlap. Measure each one, add the first with Add another area, then enter the second. The total is the room.
How do I turn inches into feet?
Divide the inches by 12, so 6 inches is 0.5 ft. You can also just type 12 6 or 12' 6" here and the calculator does it.
Why do stores sell carpet by the square yard?
Carpet has long been priced that way. One square yard is 9 square feet, so the calculator shows both.
How do I find the area of a triangle or circle?
Pick Triangle or Circle above the boxes. A triangle is base × height ÷ 2. A circle is 3.1416 × the radius squared, which the calculator works out from the diameter.
Do I subtract cabinets or a tub from the floor area?
For flooring, yes, if the floor won't go under them; most built-in cabinets and tubs sit on the subfloor. For a quote or a listing, rooms are usually measured wall to wall.
How much extra flooring should I buy?
About 10% for straight layouts and 15% for diagonal or herringbone patterns, to cover cuts and mistakes. Keep a box for future repairs.