I just put on some 305/70/18 knati mud hog on my stock fx4 18s last week and I'll be getting some 2" bora spacers here in about a week and a half. How would I go about trying to figure out the offset after I install them so I can get an idea of how much they are gonna stick out. I know the oem rims have an offset of +44.

 

This might get confusing with terms, because the spacers won't effect the actual wheel offset. What your looking for is the "effective" offset. The 2" spacers act as if adding negative offset to your OEM wheels.

There are 25.4mm in an inch. So -25.4 x 2 + 44 = 6.8mm negative.

Someone keep me honest here and validate or invalidate.

Here's a good tool to use as well. You can use this to compare to stock. https://www.rimsntires.com/specspro.jsp

 

Based on using this comparison chart http://www.rimsntires.com/specspro.j...4&text1=Sample and your dimensions, the edge of the tire would stick out ~2.6'' (~66mm) further on the outside.