This is a good read if you are uncertain about bicycle tire sizes. Old, but still applicable....
Tire Sizing Systems
There is even a table near the bottom that shows recommended rim widths vs tire width. Though that isn't a set in stone thing. It just a general thing when you have no better info. Some manufacturers like Continental Bike Tire have similar charts for their tires. Or if you are up to the task and okay with the risk, then you can test and try any combo you care to choose.