I was wondering if these sizes would fit on an FD...

18x8.5 (+37 offset)
18x10 (+41 offset)

Tried finding something out there to help figure out calculations but could only come up with tire configurations. Please help.

 

The archives hold your answer.

Those fitments are very aggressive. You will have to run 235/40 and 265/35. You may still have to roll your fenders.

 

agreed! seek higher offsets or narrower wheels.