There's not much of a difference between the two, and they can be used pretty interchangeably. In general, "acceptable" means that something is able to be agree on, while "suitable" is right or appropriate for a particular person or situation (these are the definitions from google). The difference truly just becomes semantic at a certain point. For instance, it's more common to say that toys are suitable for children ages 3-5 rather than acceptable to children (unless, of course, the children are judging the quality of the toys, and they find the toys agreeable). Also, whenever talking about limits to something, "acceptable" will typically be used. You would never say "a suitable amount of lead in the drinking water is xx." You don't want any lead in water, right? So instead, it would be better to say "an acceptable amount of lead in the drinking water is xx." I hope this helps a little!

Acceptable = tolerable Suitable = slightly better than tolerable. More tailored to a particular situation. For example, it’s acceptable to wear jeans in an office, but suit trousers are more suitable.

guess, acceptable is more general term that also includes suitable as part of it. things that could be acceptable could be rather suitable or not. suitable is something that is more according to one’s needs or interests in meaning of “best possible choice”, but even less favorable choices or things could be still acceptable