Circumference of a Circle Calculator
Calculate the circumference of a circle using the radius.
Enter the radius to see results
About
The circumference of a circle is the distance around the circle. It is calculated using the formula: C = 2πr, where r is the radius of the circle. Use this calculator to quickly find the circumference when you know the radius.
Practical example: If you have a circle with a radius of 3 units, the circumference is 2 × π × 3 ≈ 18.85 units.
Common Calculations
| Radius (r) | Circumference (C) |
|---|---|
| 1 | 6.28 |
| 2 | 12.57 |
| 3 | 18.85 |
| 4 | 25.13 |
| 5 | 31.42 |
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