Circle Calculator

Circle Calculator lets you circle area is πr² and circumference is 2πr. Enter your own values or load the worked example.

Method and calculation

Circle area is πr² and circumference is 2πr.

Inputs and settings

Circle Calculator accepts Radius (minimum 0.000001).

Worked example

Circle Calculator example — Radius: 5. Computed output: { "diameter": 10, "area": 78.53981633974483, "circumference": 31.41592653589793 }

Output and limitations

Circle Calculator: Use finite inputs. Results use double-precision arithmetic.

Technical references: JavaScript numerical operations

Circle Calculator FAQs

Circle Calculator applies the following rule to your input: Circle area is πr² and circumference is 2πr. The worked example on this page uses the same processor as the result button.
Circle Calculator has these boundaries: Use finite inputs. Results use double-precision arithmetic. Start by checking the radius field against the units or format shown.
Circle Calculator provides this sample: { "diameter": 10, "area": 78.53981633974483, "circumference": 31.41592653589793 }. Use the sample button to reproduce it, then replace the inputs with your own values.