The Imus 4-Beat® saddle seats measure smaller from cantle to pommel than they actually are when being ridden. This is because of the flexible tree bars and the web suspended seat - the webbing causes the seat area to slightly 'cup up' when the saddle is sitting on a saddle stand. However, when the rider sits in the seat, the bars flatten back out to their true, original size. This gives the rider a snug, secure feel when in the saddle - if the seat size is truly too small, then the rider doesn't feel 'snugged in,' but rather feels as though they're being pushed out of the seat.This has been a hard concept to explain to people who are accustomed to measuring seat size a certain way. The following chart should help you determine what seat size is best for you.  However, seat size/comfort is different for everyone.  This is only used as a general guide and not an absolute guarantee of fit.