A piece of string or paper is a good tool in measuring ring size.
If you are using a piece of paper, make sure to cut it into a thin, long strip.
A good size is 15cm by 0.5cm.
Wrap the string or strip of paper around the thickest part of the finger that you wish to measure, and then make a marking at the point it goes one round around the finger.
Once you have made the marking, unravel the string or paper and lay it flat.
Measure the length up till the marking, and you will get the circumference of the ideal ring size.
Thereafter, you try to match the circumference to the right ring size number.
If the circumference is in between sizes, it is better to choose the larger size.
We are measuring the inside diameter of the ring