To use a ruler to measure ring size, wrap a string around the ring finger and make a mark at the point where the string meets, and then measure the distance between the marks with the ruler. The length between the mark should be measured in inches and then compared to a ring size chart to determine its ring size equivalent.Continue Reading
The following shows one method of using a ruler to measure ring size.
Cut about a 6-inch long string. A strip of wire can also be used for this method.
Wrap the string just below the knuckle at the base of the ring finger. Make the necessary allowances for large knuckles and weight changes. Physical exercise and medication can also cause the size of the finger to change.
Using a pen, mark the area where the string meets.
Unravel the string and then measure the distance between the pen marks in inches.
Use a ring size chart to match the measurement in inches to its equivalent in ring size. The following is an example of a ring size chart from ring sizes 5 to 11.