MEASURING AT HOME
1 - MEASURE A RING YOU ALREADY OWN (PREFERRED METHOD):
This is the length in mm from one side of the band to the other, at its widest point. Starting at the inside of the band on the left and ending at the inside of the band on the right.
2 - MEASURE YOUR FINGER:
This method should be your last resort and should only be used if you do not have the option of having your ring size taken by a professional jeweller.
Take a piece of stiff cardboard, plastic or thick wire and wrap it around the finger you will be wearing the ring on - lay the piece of material flat against a ruler and use the measurement in mm as your finger circumference. This method has a larger risk of being inaccurate as we do not know how stretchy or thick the material used will be and how tightly you have wrapped it around your finger.