Area Calculator
Add up room and floor areas in square metres and square feet.
What is the area calculator?
This area calculator works out the floor area of rooms and spaces of different shapes and adds them together. You can list every room in a house, choose the right shape for each one and get a total in square metres and square feet at the same time. It is useful for ordering flooring, comparing quotes priced per square foot, checking the size of a property listing or estimating heating and cleaning costs.
How to calculate area
- Choose metric (metres) or imperial (feet) units.
- Give the first area a name, such as Bedroom, and choose its shape.
- Type the dimensions. The area of that row updates as you type, with the formula next to it.
- Press Add area for each extra room, or Remove for rows you do not need.
- Read the totals, then use Copy summary or Download CSV to keep the results.
Shapes and formulas
- Rectangle: length x width.
- L-shape: split the room into two rectangles, A and B, and the tool adds them.
- Triangle: base x height / 2, where height is measured at right angles to the base.
- Circle: pi x diameter squared / 4.
- Trapezoid: the average of the two parallel sides x the distance between them.
Adding extra for waste
When you buy flooring, carpet, turf or paving you need more than the exact area, because pieces are cut to fit and some are wasted. The calculator shows a total with an extra percentage that you set. Ten percent is a sensible starting point for straight layouts, while diagonal and patterned layouts often need fifteen percent. Set it to zero if you only need the true floor area.
Tips for measuring a room
Measure at floor level from wall to wall, and round to the nearest centimetre or half inch. For rooms with alcoves, bay windows or chimney breasts, treat each part as its own rectangle and add it as a separate row, or use the L-shape option. If you need to deduct something, such as a fixed kitchen island, calculate its area separately and subtract it from the total. Measure twice before ordering expensive materials.
Who uses an area calculator?
Homeowners use it to compare flooring and carpet quotes, which are usually priced per square metre or per square foot. Landlords and estate agents use it to check advertised floor areas. Gardeners use the circle and triangle shapes for lawns, beds and patios. Because every row keeps its own name and shape, the copied summary doubles as a simple room schedule you can send to a supplier or keep with your project notes.
Frequently asked questions
How do I convert square metres to square feet?
Multiply square metres by 10.7639 to get square feet, or divide square feet by 10.7639 to get square metres. The calculator always shows both totals.
How do I calculate the area of an L-shaped room?
Split the L into two rectangles that do not overlap, measure the length and width of each, and add the two areas. Choose the L-shape option and enter part A and part B.
Are the results exact?
The formulas are exact, but the results are estimates that depend on your measurements. Walls are rarely perfectly square, so add a margin when ordering materials.