Wrap a thin strip of paper, string, or floss around the base of the finger
Mark where the ends meet
Measure the length with a ruler in millimeters
Compare the measurement to a ring size chart
Use a ring that already fits
Place the ring on a ruler and measure the inside diameter in millimeters
Compare the diameter to a ring size chart
Measure the finger at the end of the day
Measure the exact finger where the ring will be worn
Make sure the material is snug but not tight
Repeat the measurement 2 to 3 times for accuracy
Check both hands if the ring could be worn on either hand
Use a printable ring sizer if available
Avoid measuring when fingers are cold or swollen