Please supply your trouser size as well as a measurement taken over your clothing at the position you will wear your gun belt.

Alternatively, measure an existing cartridge belt from the tip of the buckle prong to the hole you are using.

 This gives me your middle hole measurement and should be approximately 4” over your trouser size

Hollywood rigs also require a measurement from the center of your hip to your belt buckle line, taken over your pants below your trouser belt