I have only made a few belts and have used roller buckles, all of them have come out short using different methods to size it. The part I am missing is "adding couple inches" to waist measurement.
13 year old granddaughter, waist measurement over jeans is 30 1/2 inch, buckle bar to hook is 2 1/4 inch, want to use 4 holes ( wear hole, 1 smaller 2 bigger )
So......Fold to wear hole 30 1/2 plus couple inches (32 1/2) minus the 2 1/4 for buckle = 30 1/4 from fold to wear hole ?
JLS love your " 3 hole " method