Circumference Calculator
Calculate circle circumference from radius, diameter, or area, and optionally find an arc length from a central angle.
Circle circumference from radius or diameter
English search intent is direct: enter radius or diameter and get the distance around a circle. The tool also handles area-to-circumference and optional arc length checks.
| Known value | First step | Output |
|---|---|---|
| Radius | Use radius directly | Circumference, diameter, area |
| Diameter | Convert to radius | Circumference |
| Circle area | Recover radius from area | Circumference |
| Arc angle | Use a fraction of the full circle | Arc length |
Circumference formulas
C is circumference; r is radius.
d is diameter.
L is arc length; alpha is angle in degrees.
Frequently Asked Questions
Sources and References
- CircumferenceWolfram MathWorld
- Circle CalculatorCalculator.net
- Circumference CalculatorOmni Calculator
Calculations are based on the listed reference sources. Links open in a new tab.
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