How do you know if you can pull off a wide brim in these days of stingy hats?
Just try it, and use your own eyes to judge proportions and silhouette. You may never want to wear stingies (2" and narrower) again...
Just be aware that every 1/8" makes quite a difference. Some folks around here prefer the 2 1/8"-2 1/4" range for dress hats, others perhaps 2 3/8"-2 1/2", and so on up to the 2 3/4" full brims.
Non-stingy brims are somewhat comparable to double-pleated trousers... Wear them once - chances are you will never want to switch back (to flat fronts, in the case of suit pants I mean).