Circumference to Diameter

Free Circumference to Diameter converter with instant calculations. Trusted by millions worldwide. Includes conversion charts, formulas, and step-by-step exa...

1 Circumference = 0.31831 Diameter (standard conversion factor). · Updated 2026-05-29

Circle Calculator

Circumference to Diameter Conversion Table

Common Circumference to Diameter conversion values

Circumference Diameter
1 C 0.318 d
10 C 3.183 d
50 C 15.915 d
100 C 31.831 d
500 C 159.155 d
1000 C 318.310 d

The formula

Circle conversions use π-based geometry (radius, diameter, circumference, area).

Example: 1 Circumference = 0.31831 Diameter