Another way to be sure is to invest a few bucks in one of those flexible measuring tapes used by seamstresses, tailors, etc. Can find them at Wal Mart in the fabric aisle (or Hobby Lobby etc). When you get your gun/holster (assuming IWB here), put it all on over your underwear (do this AT HOME and IN PRIVATE please
), then measure - loosely - around your waist with everything in place. This is generally the size pants and belt you'll need. A lot of this depends on your body type, shape, size etc.
Also if a belt maker has specific instructions for how to measure the proper size of that particular belt, then follow THOSE directions - each maker does things a bit differently.
and
++++ on the quality belt recommendation. Makes all the difference in the world. Here is a plentiful list of suggested makers/types of quality belts ... viewtopic.php?f=23&t=45576&hilit=belt+poll" onclick="window.open(this.href);return false;