Area Calculator
Calculate the area of a rectangle, circle or triangle.
Result
Results are estimates for general information only and are not professional advice.
Area formulas
Rectangle area is width × height, circle area is π × radius², and triangle area is ½ × base × height. Choose a shape, enter the dimensions and the calculator returns the area instantly.
Frequently Asked Questions
What is the Area Calculator?
Calculate the area of a rectangle, circle or triangle. It runs instantly in your browser and is completely free to use.
What do I need to enter to use the Area Calculator?
The Area Calculator asks for the following values (3): Shape, Width / Radius / Base, Height (rectangle/triangle). Fill them in and the result appears immediately — the calculation runs on your own device, so nothing you type is sent to a server.
How accurate is the Area Calculator?
The Area Calculator uses standard, widely-accepted formulas, so its figures are reliable estimates for everyday planning. They are not a substitute for advice from a qualified professional.
Is the Area Calculator free, and do I need an account?
Yes. The Area Calculator — and every other calculator on Calculatis — is completely free, with no registration, no download and no limit on how often you use it.