Tool capabilities
- Input
- Options
- Output
- Options
How to use Circle Area
Calculate area and circumference from a radius. This circle area works directly in your browser and is free to use without an account.
- Enter the values in the labeled fields using consistent units.
- Read the calculated result, supporting values and formula.
- Adjust an input to compare another scenario or copy the result.
Circle Area · Example
Input
Radius: 5
Output
Area (square units): 78.53981633974483 Circumference: 31.41592653589793
Formula: π × radius²
Usage notes
Inputs and results are processed on this device. Tool content is not sent to a processing server.
Calculations use the displayed assumptions and ordinary floating-point arithmetic. Rounding may affect the last displayed digits.