To figure out your perfect fit measure a well fitting belt from the place at which the buckle is attached to the most used hole. You can also use your trouser size to determine your belt size, but please bear in mind this can vary depending on the height that you wear your trousers. 

From this measurement you can pick out which sized belt will covers your size, all our belts have enough holes to provide you with some wiggle room either way too.

If you need any help deciding, please feel free to ask!