I have an existing ring to measure
Select an existing ring that fits the desired finger.
Measure the internal diameter of the ring (in mm).
Use the below chart > Diameter < to determine your ring size.
I don't have an existing ring to measure
Tips & Tricks
Measure your ring size at the end of the day when fingers are at their largest.
Consider the width of the band, a particularly thick band will feel tighter than a thin band so you may want to buy a full size larger that your normal ring size.
Do not measure your hands when they are cold, they may have shrunk up to half a size.
Alcohol and salt can make your fingers swell so refrain from measuring your ring size after cocktails and appetizers.