Depends which Order of Merit you're talking about. The Academy has Academic Order of Merit, Military Order of Merit, and Overall Order of Merit. Academic Order of Merit is simply the academic standing within the class determined by GPA (or QPR as we call it). Military Order of Merit is this mysterious number spit out by an algorithm that takes into account military class grades, professional competency, conduct, PRT, etc. Overall Order of Merit is determined by adding AOM and MOM and then ranking from least(top of class) to greatest(bottom of class).