Find the area of common shapes instantly with this free area calculator. Choose a rectangle, square, circle or triangle, enter the measurements, and get the area in square units — handy for flooring, painting, gardening and homework.
How to Use
- Choose the shape you want to measure.
- Enter the measurements — the labels update for each shape.
- Click Calculate to see the area and the formula used.
- Use Reset to clear the form and measure another shape.
Key Features
- Four common shapes. Rectangle, square, circle and triangle covered in one tool.
- Shows its working. The formula used is displayed with every answer.
- Decimal friendly. Enter fractional measurements such as 2.5 with no problem.
- Private and instant. Everything runs in your browser; no data leaves your device.
- Free, no sign-up. Measure rooms, gardens and project areas as often as you like.
FAQs
What units is the answer in?
Square units of whatever you enter. If you measure in metres, the answer is in square metres; if you measure in centimetres, it is in square centimetres.
Does the circle use radius or diameter?
It uses the radius. If you only know the diameter, simply halve it before entering.
Can I enter decimal measurements?
Yes. All fields accept decimals, so measurements like 3.75 are no problem.
Is any of my data stored?
No. All calculations happen locally in your browser, and the measurements you enter never leave your device.