Circle Area Calculator

Circle Area Calculator

Calculate circle area, circumference, radius, and diameter instantly with our free circle calculator. Perfect for geometry homework, engineering projects, and design work. Get accurate results with step-by-step solutions and support for any measurement input.

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area
circumference
Common Circle Examples
Click examples to try circle area calculations instantly
1Circle Measurements
Enter any one measurement to calculate area, circumference, and all other measurements
How it works: Enter any one measurement (radius, diameter, or circumference) and the calculator will find all other measurements using the relationships: r = d/2 = C/(2π), Area = πr², C = 2πr.

Complete Guide: Circle Area Calculator

Everything you need to know about using Circle Area Calculator effectively