Square Footage Calculator — Area of a Room
Add up the square footage (and square metres) of one or more rooms, with an optional total cost per square foot. Free, in your browser.
🔒 Calculated in your browser — nothing is uploaded.
Total area, room by room
Enter the length and width of each room or area and the tool sums them into total square feet and square metres. Add as many areas as you like — L-shaped rooms are just two rectangles. Enter a price per square unit to also get a total cost for flooring, carpet or tiling.
Feet or metres
Switch the unit and enter measurements in the system you’re working in; both the ft² and m² totals are always shown. Everything is calculated in your browser — nothing is uploaded.
Rooms that are not rectangles
Add a row per rectangle and the total is their sum, which is how every awkward room is measured in practice. An L-shape is two rectangles. A room with a chimney breast is the room minus a small rectangle — enter it as a second row and subtract it yourself, or measure the two remaining strips instead. For a bay, take the widest and deepest points and accept that you have overestimated slightly, which is what you want when buying material. A triangle is half its base times its height, so enter half the base as one side.
Feet and metres do not convert the way lengths do
One metre is 3.28 feet, so it is tempting to reach for 3.28 when converting an area. It is wrong: area converts by the square, and one square metre is 3.28² = 10.764 square feet. Getting this backwards is the most common error in a flooring quote, and it is out by more than a factor of three. The tool converts both ways so you never have to, but the price you enter must be per the same unit you measured in — per square metre if you measured in metres, per square foot if you measured in feet.
Frequently asked questions
How do I calculate square footage?
Multiply length by width for each rectangular area and add them up. For odd shapes, split them into rectangles — this tool sums multiple areas for you.
How do I convert square feet to square metres?
Divide square feet by 10.764. The tool shows both totals at once, so you don’t need to convert by hand.
My room is L-shaped. How do I measure it?
Split it into rectangles and add a row for each. Any shape made of straight walls at right angles can be cut into rectangles, and their areas add up to the whole.
Why is one square metre not 3.28 square feet?
Because area scales by the square of the length factor. One metre is 3.28 feet, so one square metre is 3.28 × 3.28 = 10.764 square feet. Using 3.28 for an area underestimates it by more than three times.
What unit should the price be in?
The same unit you measured in — per square metre for metric rows, per square foot for imperial. If your quote is in the other unit, convert the price first: divide a per-square-metre price by 10.764 to get per square foot.