Circle Calculator
Calculate area, circumference, diameter from radius or calculate all circle properties from any single known value.
How to Use Circle Calculator
The Circle Calculator computes all circle properties from any single known value. Select what you know — radius, diameter, circumference, or area — enter the value, and the tool calculates all other properties instantly. Uses the formulas C = 2πr for circumference and A = πr² for area. Results are shown with 6 decimal places for precision. Perfect for geometry homework, engineering calculations, construction planning, and any situation where you need to work with circular measurements. The formula used is displayed alongside results.
Step-by-Step Instructions
- Select what value you know (radius, diameter, circumference, or area)
- Enter the known value
- Click Calculate to see all circle properties
- View radius, diameter, circumference, and area results
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