In my opinion there is no limit to the number of classes you can offer. It usually depends on the demographics, your philosophy and the type of classes you are looking to provide. Usually a morning and an afternoon class 3-4 days a week should be a good point to start from. Since I don’t know anything about your club, the location and the type of your services, it’s difficult to be more specific.
In general, I would start with an early class (before work) often times 5:30 am daily. Then an afterwork class daily 5:30 or 6 pm. Other times are right after moms drop kids off at school. 9 am or so. From there once they fill up you can add classes next to them to take pressure off that specific time. Above answers are right on also. It all depends on what you are going for.
I agree with the above answers that it depends on the type of clients who are at your club already, plus the type of clients you want to attract. Since you have a small club, you could always poll them to see how they currently use the gym, whether they’d actually attend classes and what types of classes they’d like.
Some places are cardio driven, i.e. Brick House Cardio club that is all classes and virtually no machines. Other places like Planet Fitness have no classes at all.//