Cut a thin strip of paper, wrap it around your finger, mark the paper where it meets and then measure it with a ruler. Then you can compare it to our chart of ring sizes below:
Ring Size Paper Length in Inches
4 1 13/16
5 1 15/16
6 2 1/16
7 2 1/8
8 2 1/4
9 2 5/16
10 2 7/16
11 2 9/16
12 2 5/8
13 2 3/4
14 2 7/8