Wrap a strip of paper, string, or floss snugly around the base of the finger
Mark the point where the ends meet
Measure the length with a ruler 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 slightly larger
Measure the exact finger and hand you will wear the ring on
Make sure the paper or string is snug, not tight
If the knuckle is larger, measure both the base and knuckle
Choose a size that can slide over the knuckle comfortably
Use an existing ring that fits well and measure its inner diameter
Match the inner diameter to a ring size chart
Check your size in warm and cool conditions if needed
Use a printable ring sizer if available
Confirm the size with a jeweler if you want the most accurate fit