Circle Area & Circumference Calculator

Calculate circle area and circumference from radius, diameter, or circumference. Enter the known value and get instant, precise results.

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Understanding Circle Calculations: Formulas and Properties

A circle is a closed curve in geometry where all points are equidistant from a fixed center point. The fundamental properties of a circle include radius, diameter, area, and circumference.

Area represents the space enclosed by the circle and is calculated using A = π × r². Circumference is the perimeter of the circle, calculated as C = 2 × π × r. This calculator uses these fundamental formulas to compute other values from radius, diameter, or circumference.

Frequently Asked Questions About Circle Calculations