Square Footage Calculator
Measure one room or a whole floor: add rectangles, circles and triangles, subtract cut-outs, and get square feet, square metres, square yards and acres.
- Multiple rooms
- Subtract cut-outs
- sq ft, m², acres
- Cost estimate
Measure your rooms or areas
Enter feet (12), feet and inches (12' 6" or 12 6) or inches (18in).
120 sq ft
Total area of 1 area.
- Square metres
- 11.15 m²
- Square yards
- 13.33 sq yd
- Acres
- 0.0028
What is square footage?
Square footage is the area of a surface measured in square feet. It is the number you need to buy flooring, paint coverage, sod, carpet or tile, to compare home prices, and to estimate cleaning or renovation costs. For a rectangle it is simply length × width. Real spaces are often L-shaped or include bay windows and islands, so this calculator lets you add several shapes and subtract the parts you do not want to count.
How to use Square Footage Calculator
- Choose feet and inches or metres.
- Measure each rectangular section of the room or lot and enter the length and width. Use Circle or Triangle for curved or angled parts.
- Add more areas for L-shaped rooms or several rooms, and tick “Subtract” for islands, fireplaces or ponds.
- Read the total in square feet, plus square metres, square yards and acres. Add a price per square foot for a cost estimate.
How to calculate square footage
- Rectangle: length × width. A 12 × 10 ft room is 120 sq ft.
- L-shaped room: split it into two rectangles and add them.
- Circle: π × radius². A 10 ft diameter circle is about 78.5 sq ft.
- Triangle: base × height ÷ 2.
- Conversions: 1 m² = 10.764 sq ft, 1 sq yd = 9 sq ft, 1 acre = 43,560 sq ft.
Why use this square footage calculator
- Several areas at onceAdd rectangles, circles and triangles, set quantities and subtract cut-outs to match real, irregular spaces.
- Feet, inches or metresType 12' 6" or 12 6, switch to metres any time, and see results in both systems.
- Every unit you needSquare feet, square metres, square yards and acres from one set of measurements.
- Budget in secondsAdd a price per square foot to estimate flooring, carpet or sod costs.
Common projects
- Flooring and carpet. Total the floor area of several rooms before ordering.
- Selling or renting. Check a listing’s square footage or price per square foot.
- Lawns and gardens. Measure a yard for sod, seed or fertiliser.
- Painting and cleaning quotes. Give contractors an accurate area.
Planning a bigger project? See all home and DIY calculators, or work out costs with the percentage calculator and discount calculator.
Example: an L-shaped living room
Split the room into a 15 × 12 ft section and a 6 × 8 ft alcove: 180 + 48 = 228 sq ft. Subtract a 3 × 4 ft fireplace hearth: 216 sq ft of flooring, which is 20.1 m² or 24 square yards.
What to expect from the result
Accuracy depends on your measurements; measure to the nearest inch and round up when buying materials. Official home square footage follows specific standards (for example ANSI Z765 in the US) that exclude some spaces.
Square Footage Calculator questions
How do I calculate square footage?
Multiply the length by the width in feet. For irregular spaces, split them into rectangles, circles and triangles, calculate each and add them up. This calculator does it for any number of shapes.
How do I calculate the square footage of a room with an odd shape?
Divide it into simple shapes. Add a rectangle for each section, use triangles for angled corners, and tick “Subtract” for parts that should not count.
How many square feet are in a square metre?
One square metre is 10.764 square feet. The calculator shows both.
How do I convert square feet to acres?
Divide by 43,560. A 10,000 sq ft lot is 0.2296 acres.
Should I add extra when buying flooring?
Yes, usually 5–10% for cuts and waste, or 15% for diagonal layouts. Use the tile calculator for tile counts with waste.