Rings are measured differently in different countries. In Sweden, the most common way is to measure the inner diameter (mm) or inner circumference (mm), which is how we do it at PKF Design.
The very best way to measure your ring size is to visit a jeweller and ask them to measure your size, but there are other ways to measure, that you can do by yourself, at home.
In our webshop we sell a tool for measuring ring sizes. The tool takes measure of the circumferens of the finger. We recommend you to buy the tool before ordering a ring online since that makes it easy to measure and is easy to use.
If you don’t wish to buy a ring measure tool, there are other ways of measuring. The most simple way is to measure the inner diameter of a ring you alredy have and that you know fits well, using callipers or a ruler as shown in the pictures below. You would get the best result using callipers.
Place the ring on top of the ruler as you see in the picture. With the ruler we can see that the inner diameter is 18 mm.
Using the callipers, we can see that in fact the inner diameter is 18,1 mm, as the tiny 1 in the lower part pairs with the line above.
Another way would be to take a pice of a string or thread and wind it around your finger, make a mark where the string meets the end and then measure the length between the end of the string and the mark. This way you measure the circumference.
The best way to use this method is to have someone else to help you as it is hard to make a correct measure doing it on yourself.
Remember that the size changes with the temperature of your hand. If you are warm, the finger is larger and if you are cold, the finger is thinner. The best time to measure is when your hand temperature is in between and also not to tighten the string around the finger.
Also keep in mind that wider rings often have to be a couple of sizes bigger since they cover a larger part of the finger. If, for instance, you have a size 55 (mm circumference) on a 3mm wide ring you might need a size 57,5 (mm circumference) on a 11mm wide ring.
Please measure several times to make sure that you find the right size!