On our e-shop we use the United States system (US) and diameter in mm or inches.
If you already know your size, you can compare it between international ring size systems in the table below.
Or if you don’t know how to choose your ring’s size follow this advises:
measure the inner diameter of the ring with a ruler
measure the circumference of your finger, with a thread.
For this second way: take the measurement with the thread around your finger, then lay the thread on the table and measure its length with a ruler.
Remember: the ring must be wide enough to pass comfortably, but not too much, so as not to risk losing it.
Take measurements when your hands are neither too hot or too cold.