Let's talk about trucks

This barely fits as in it's about a minivan, which are "trucks" according to the parts listings.
but when differentiating between 2 possible parts for a given vehicle, why are all measurements in MM these days??? I had a grand caravan in yesterday, and supposedly there were 2 possible (different) rear brake rotors it could have come with. When I had the parts guy on the phone he asked me if the rotors were 232 mm. My question was " do they show an inch equivalent?" My tape measure shows inches not mm.
I ended up having to find an inch to mm conversion on the phone to be able to answer the question and (hopefully) wind up with the right ones.
Right! Big PITA. The worst were the GM cars of the mid 70s through even the early 90s. A mixture of BOTH standard AND metric sizes all over those cars. Just plain stupid. A drunk toofless hillbilly couldda made a better car.

No offense to drunk toofless hillbillys.