The simplest way to find your belt size is to select the most comfortable belt that you own. Lay the fully extended belt on a flat surface. Measure the distance, in inches, from the hole that is most comfortable (the hole you buckle it in) to where the belt folds around the buckle. Do not include the length of the buckle. This number is your correct belt size. If the measurement number is an odd size, order the next even size. Example: your belt measures 33 inches, order a size 34 belt.
Ladies, or if you don’t have a belt that fits:
Break out the old measuring tape. This really is important. Don’t try to guess, or assume you wear a certain size, just because the last belt you bought was that size. Instead, break out the measuring tape and measure exactly how and where you like your belt to sit on your hips, making sure to put the tape through your belt loops. When choosing your belt size add some extra inches if you intend to wear the belt on the outside of your shirt.