Need advice on used wheels for 328i GT

[cidion]

I have a 2014 328i GT with 17in stock wheels.
I'd like to find a used set of 18in better looking wheels. But I want to know what to look for as far as sizing and offset goes.
Since I'm buying used I don't want to get them and... whoops, they don't fit.

It seems like there are a lot of variables, but I don't know if some of them need to be exact, or close.

Is there an easy way to work that out?
This feels like a simple problem, but I'm still stumped.

[Pelican Parts]

Hello - take a look at the link below on wheel fitment and spacing/offset. It's a great, easy-to-understand guide. Please let us know if you have any questions!

Wheel Fitment & Spacing Guide