Find the size of the ring you need from a circumference 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 diameter.
In this calculator, 35.99 mm is a size 0 ring and at the upper end, 112.5 mm is a size 29 ¾ ring