Get the US ring size from the circumference of your finger measured in inches.

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

The circumference measurement needed is in decimal inch format. The whole number is entered as is, but a fraction has to be converted to a decimal, and you do this by dividing the numerator by the denominator.

example:

2 7/16" = 2 + (7 ÷ 16) = 2.017857 in decimal inches
1 5/8" = 1 + (5 ÷ 8) = 1.625 in decimal inches
1 3/16" = 1 + (3 ÷ 16) 1.1875 in decimal inches

Note:

In this calculator, 1.43885" is a size ¼ ring and on the upper end, 4.45478" is a size 30 ring

Calculation

1. finger's circumference in inches

Result

1. the inside ring diameter in decimal inches
2. the inside ring diameter in inch plus a fraction
3. US ring size