Tires: Optimal Wheel Sizing, rim width, tire sizes

Question
How do you determine the optimal wheel sizing for various tire sizes and what is the allowable variance (plus or minus)?

Answer
Jim,

I can appreciate that I didn't answer your question directly, but the formula for rim width is indeed complex and there are some exceptions that the tire standardizing organization has made - which is why it is easier and more accurate to start with the tire size and do a table look up  - and that's what the tire calculators do.

BTW, I went to 1010tires.com and input a tire size and one of the lines in the response is allowable rim width.

Perhaps it would be better if I understood what you were trying to do - particularly if you have a particular tire size in mind.