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Diameter Calculator – Calculate Circle Diameter

Calculate circle diameter from radius, circumference, or area

Calculate Diameter

How to Use

  1. Select input type (radius, circumference, or area)
  2. Enter the known value
  3. Click calculate to see the diameter
  4. Review the calculated diameter

What is Diameter?

The diameter of a circle is the straight line passing through the center of the circle, connecting two points on the circumference. It is twice the length of the radius and is the longest chord of the circle.

Diameter Formulas

  • From radius: d = 2r
  • From circumference: d = C/π
  • From area: d = 2√(A/π)

Frequently Asked Questions

How do I calculate diameter from radius?
To calculate diameter from radius, simply multiply the radius by 2. The formula is d = 2r, where d is diameter and r is radius.
What is the relationship between diameter and circumference?
The circumference equals π times the diameter (C = πd). Therefore, diameter equals circumference divided by π (d = C/π).

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