1. Wrap a piece of string around your finger

2. Take a pen and mark where the string overlaps

3. Stretch the string out across a ruler to get the length in millimeters

4. Use this guide to calculate your ring size:

· 14 mm = size 3

· 14.8 mm = size 4

· 15.6 mm = size 5

· 16.5 mm = size 6

· 17.3 mm = size 7

· 18.2 mm = size 8

· 19 mm = size 9

· 19.8 mm = size 10

· 20. 6 mm = size 11

· 21.4 mm = size 12

· 22.2 mm = size 13

Women are generally between a size 6 and 7
while the most common sizes for men are 10 and 11.