Ring Size Chart

Ring sizes look like arbitrary numbers and letters, but every standard in the world is derived from a single physical measurement: the inner diameter of the band, in millimetres. That is the number in the second column. Once you know it, every other column follows automatically.

The United States and Canada use a numeric scale that runs in quarter and half sizes. The UK, Ireland and Australia use letters, where each letter is roughly half a US size. Continental Europe uses the inner circumference in millimetres rounded to the nearest whole number, which is why EU sizes look like 51, 54 or 62. India uses its own numeric scale that runs from 0 upward in single increments.

Diameter and circumference describe the same ring. Circumference is simply the diameter multiplied by pi, so a 17.32 mm diameter gives a 54.4 mm circumference. If you measured your finger by wrapping string or paper around it, you measured circumference — use that column rather than the diameter one.

The average ring size for women is a US 6 to 7, an inner diameter of roughly 16.5 to 17.3 mm. The average for men is a US 10, or about 20.2 mm, and the men's ring size chart covers that range in detail. Averages are only useful as a last resort though — finger size varies enormously between people of the same height and build.

Bear in mind that a chart alone cannot tell you your size. You still need a real measurement to look up, which is what the sizing tools below are for.