MEASURE A BELT
I have a belt
It's easy to measure a belt. Simple take your existing belt and lay it flat on a table. With a fabric tape measure place the end of the tape at the tip of you current belt. From there measure down to the most used hole, this is your belt size.
**Sometimes belts will get deformed and will end up with a bent in the middle. This will impact your measurement, so be sure to straighten your belt as best as possible to get an accurate measurement.
I don't have a belt
If you don't have an existing belt it's easy to measure your waist. Take a fabric tape and loop it through the belt loops on your waist. Make sure the tape isn't pulled to tightly.