Measure from a Ring
Before you sit down to measure your ring size, there are a few how-to pointers you should keep in mind:
Consider your knuckle. If you know your knuckle is on the larger side, you should order half a size bigger than what your finger alone indicates, otherwise you won’t be able slide a ring into the right place.
Ensure accuracy with multiple tries. Catbird’s site recommends measuring your finger three to four different times because the size actually fluctuates depending on temperature: It can be smaller the colder you are and more swollen if you’re overheated.
You can measure your ring size using a piece of jewelry that you already have and know fits you. Print out a true-to-size ring size chart—like this one from Catbird—and place your ring on the circles until you find the one that matches up with the inside circumference of your ring.