Use a calliper or a ruler to measure the inside diameter of the ring. This measurement, expressed in mm, can be used to determine the correct ring size. Simply download our conversion chart below, where you can find the diameter measurement in the last column and the matching ring size in the first column.

Use our comparative table if you know the ring size in a different country or measuring system than the one we use.

A paper ring sizer works the same way as a synthetic ring sizer. You can print, cut and use this paper ring sizer to determine the correct ring size. Make sure you are printing in the correct scale. If the scaling is correct, this method is quite reliable.