Circle Calculator
Calculate Area, Circumference, Diameter, and Radius of a circle.
Circle Dimensions
r
Properties
Diameter (d = 2r)20.0000
Circumference (C = 2πr)62.8319
Area (A = πr²)314.1593
Geometry Solver
Just enter one value (like radius) and solved everything else about the circle instantly. Perfect for homework or design tasks.
Frequently Asked Questions
What is Pi (π)?
The ratio of a circle's circumference to its diameter, approx 3.14159.