More
More
Square Footage Calculator
Area of rooms and plots from rectangles, circles, triangles and trapezoids, in square feet and square metres.
Free tools that run in your browser. Nothing you type, open or create is uploaded to NerdBible or anyone else.
| Shape | ft² | m² |
|---|
Lengths are entered as decimals: 6 inches is 0.5 ft and 3 inches is 0.25 ft; 50 cm is 0.5 m. Measure an L-shaped room as two rectangles, and use an area to subtract for a chimney breast, a kitchen island or anything else you will not cover.
How to use it
- Pick Metric or Imperial.
- Choose a shape for the first area and enter its measurements.
- Add more shapes for the other parts of the room or plot, and add any areas to subtract.
- Read the total in square feet, square metres and square yards.
Questions
How do I work out square footage?
For a rectangle, multiply the length by the width in feet. A room 12 ft by 10 ft is 120 square feet. For other shapes this calculator uses the standard formulas and adds the pieces together.
Which formulas are used?
Rectangle: length x width. Circle: pi x radius squared, from the diameter. Triangle: half of base x height, where the height is measured at right angles to the base. Trapezoid: the two parallel sides added, halved, times the height between them.
How do I measure an L-shaped or irregular room?
Split it into rectangles and triangles that do not overlap, measure each one and add them as separate shapes. Anything inside the outline that you will not cover can be added as an area to subtract.
How do I convert square feet to square metres?
One square foot is 0.092903 square metres, and one square metre is about 10.764 square feet. The total is always shown in both, whichever units you measure in.
About this tool
About the square footage calculator
Flooring, paint, turf, carpet and many other materials are bought by area. Few rooms or gardens are a perfect rectangle, so this calculator lets you build the area from several shapes and take away the parts you will not cover.
Shapes and formulas
- Rectangle or square: length times width.
- Circle: pi times the radius squared, worked out from the diameter.
- Triangle: half the base times the height.
- Trapezoid: the two parallel sides added and halved, times the height between them.
Each shape can be repeated with a quantity, and any shape can be added as an area to subtract, such as a fireplace, a kitchen island or a pond.
Results
The total is shown in square feet, square metres, square yards and square inches, with a line for each shape when there are several. Measure in feet or metres; switching units converts what you have typed.
Measuring tips
Split an L-shaped room into two rectangles that do not overlap. Enter inches as decimals of a foot: 6 inches is 0.5 ft. Add a little extra to your order for cutting and waste.
Related tools
- Tile CalculatorHow many tiles and boxes for a floor or wall, with grout gap and waste.
- Concrete CalculatorConcrete for a slab, footing, column or steps in cubic metres or yards, and how many bags.
- Gravel, Mulch & Soil CalculatorVolume and weight of gravel, sand, soil or mulch for an area and depth.
- Unit ConverterLength, weight, temperature, data and more.