I am trying to get an estimate of the work load/average number of hours for a 15 credit workload. I know their are a lot of factors but I understand students will spend about 15 hours in class. How much additional study and homework time does the typical student spend?
It varies a ton from week to week. A lot of the time I spend is studying for exams, but I typically only study the night before. I would say I have a baseline of 5 hours per week outside of class when I don’t have any exams or projects. Each exam probably takes 2-5 hours to study for, and group projects can also take a long time. It’s hard to put a number on it.
I’d ball park an additional hour per hour in class 
maybe half an hour for every credit you’re taking. K201, C104, and A100 will vary person by person.