Galco COP belt sizing question

[Jacobman]

Hi all, I am looking at this belt and had a question on sizing. On their website they say to measure form the end of the buckle to the hole you use and add a size or so for IWB use. The hole I use w/o IWB puts it at 36" and with IWB 37". So since the measurement is with IWB carry already should I be good to go with a 38? Any experience from anyone who has these would be great.

Sizing instructions:

Galco holsters; Holsters; Gun holster, pistol holsters, western holsters, shoulder holsters, leather holster and Glock holsters

[DefensiveCarry.com]