How to use the circle radius and area from circumference calculator
Find the radius and area of a circle from its circumference. Enter circumference in the field above; the radius, area are computed instantly and plotted on the chart so you can see how the answer changes.
Common searches this calculator answers include “circle area from circumference”, “radius from circumference”, “circle calculator”, “calculate circle radius and area from circumference”, “find radius”.
Formula
Variables
- C — Circumference (cm)
Worked example
With circumference = 31.4 cm, the calculator gives radius ≈ 4.997465 cm; area ≈ 78.4602 cm².
Frequently asked questions
What is the circle radius and area from circumference calculator used for?
Find the radius and area of a circle from its circumference. It helps with questions such as “circle area from circumference”, “radius from circumference”, “circle calculator”.
What is the formula for the circle radius and area from circumference calculation?
Radius (cm) = C / (2 × π). Area (cm²) = π × [Radius] × [Radius]. Here C is circumference (cm).
What inputs do I need for the circle radius and area from circumference calculator?
You need circumference in cm. Each field is pre-filled with a typical example so you can see how the result responds as you edit the numbers.
How do I use the circle radius and area from circumference calculator?
Type values into the input fields. Results and the chart update instantly. Use Reset to restore the example values, Copy results to paste them elsewhere, or Share to copy a link that preserves your inputs.
Is the circle radius and area from circumference result exact?
Calculations use standard formulas and double-precision arithmetic, then display about seven significant figures. Real-world measurements carry uncertainty, so treat results as estimates unless your inputs are exact.