Take a ring that fits your waist and put it on a ruler. The inner circle of the ring (= the inner diameter) is equal to your size.
Some advice :
- If you hesitate between 2 sizes, always take the bigger one
- The size of your fingers differs according to the temperature
- If you buy a large ring, choose a size bigger than your usual size. Wide rings tend to tighten more.
Size Matrix Size / Inside Diameter