Use a ring you already wear on the same hand and finger
Measure the inside diameter of the ring in millimeters using a ruler or calipers
Convert the inside diameter to your ring size using a ring size chart (mm to size)
Alternatively, measure your finger circumference
Wrap a flexible measuring tape around the base of the finger and record the circumference in millimeters
Convert the circumference to your ring size using a ring size chart (mm to size)
If you don’t have a measuring tape, wrap a strip of paper or string around the finger
Mark where the overlap meets, then measure the length in millimeters
Convert the length to your ring size using a ring size chart
Check sizing with a printable ring sizer if available
Measure at the time of day your finger is typically largest (often later in the day)
Account for comfort fit by adding or subtracting a small amount based on preference
Recheck measurements if you fall between two sizes