What is your ring size ?
There are two ways to know your ring size :
1. Have your finger measured by a jeweller using a ring gauge (a selection of metal rings in all the different ring sizes which are fitted onto your finger until the best fit is found) or a triboulet (ring mandrel) which measures the inner circumference of an existing ring.
2. Measure the inner circumference of the ring by yourself.
You can do this by printing out the drawings of rings with different diameters which you will find below. Make sure that the 10 cm drawing actually measures 10 cm on your printout. Place a ring in your size (such as a wedding ring) on the paper. When your ring fits exactly onto one of the rings on the paper, you will have found your ring size.
You can also use a calliper to measure the inner diameter of a ring. The equivalent measurement will be your ring size.