Wrap a strip of paper or string around the base of the finger
Mark where the ends meet
Measure the length in millimeters
Compare the measurement to a ring size chart
Repeat the measurement 2 to 3 times for accuracy
Measure at the end of the day when fingers are largest
Make sure the paper or string is snug, not tight
Measure the exact finger the ring will be worn on
If between sizes, choose the larger size
Use an existing ring and measure its inner diameter
Match the inner diameter to a ring size chart
Consider band width when choosing the size
Check sizing with a jeweler for the most accurate result