Circle Calculator
Calculate the area and circumference of a circle from its radius.
- Free Online Tool
- Instant Results
- Mobile Friendly
- No Installation
- Secure & Private
Result
Understanding This Calculator
Circle Formulas
The area and circumference of a circle are calculated based on its radius (r).
- Area = π × r²
- Circumference = 2 × π × r
- Diameter = 2 × r
Example 1
Radius = 5
- Area: 3.14159 × 5² = 3.14159 × 25 ≈ 78.54
- Circumference: 2 × 3.14159 × 5 ≈ 31.42
Example 2
Radius = 10
- Area: 3.14159 × 10² = 3.14159 × 100 ≈ 314.16
- Circumference: 2 × 3.14159 × 10 ≈ 62.83
How to Use
- Enter the radius of the circle.
Frequently Asked Questions
How do I use the Circle Calculator?
Enter your values in the input fields, and the result will appear instantly.
Is this calculator free to use?
Yes, this calculator is 100% free and does not require any registration or subscription.
Is it mobile-friendly?
Absolutely! Our tool is optimized for all devices, including mobile phones, tablets, and desktop computers.