To know your size, use a piece of rope to wrap around your finger, cut or mark the rope where the two ends meet, and measure with a ruler.

Ring sizes are listed in milimeters (diameter). You can also use the table below to help you figure out your size. Remember some rings can be adjusted for size:

Diameter	Circumference
17 mm	54 mm
18 mm	57 mm
19 mm	60 mm
20 mm	63 mm
21 mm	65 mm
22 mm	67 mm
22.5 mm	70 mm