How to use the Area Calculator
- Choose the shape.
- Enter the measurements shown.
- Read the area and perimeter in the same units squared.
What does this tool do?
Area is the amount of flat space inside a shape. Every shape has its own formula — length × width for a rectangle, ½ × base × height for a triangle, πr² for a circle.
Use any unit you like. If you enter metres, the area is in square metres; if you enter feet, it's in square feet. Convert between them with the Area Converter.
Why use it?
- Ten shapes in one place.
- Perimeter included.
- Formula shown for each shape.
Privacy
The calculation happens instantly in your browser. The numbers you enter are not sent to our servers or saved. There's no account to create and nothing to install.
Frequently asked questions
How do I find the area of an irregular room?
Split it into rectangles and triangles, find each area, and add them up.
Last reviewed by the M2Toolkit team.