US Ring Size from Diameter in Millimetres

Find the size of the ring you need from a diameter measurement in millimetres of your finger.

The US ring size is used in North America, including Mexico, Canada, and the United States.

In addition to the size of the ring you need, this calculator will provide the ring's inside circumference.

Note:

In this calculator, 11.45 is a size 0 ring and at the upper end, 36.017 is a size 30 ring

Calculation

1. enter a finger's diameter measurement in millimetres

Result

1. inside ring circumference in millimetres
2. US ring size