The standard estimate is that you should spend 3 hours per week per credit hour, including in-class and out-of-class time. This means 45-48 hours per week for a 15-16 credit hour course load needed to graduate in 8 semesters.
In practice, weekly time spent in college has been declining over the years. However, you should expect a relatively higher time commitment for courses with the following:
- Labs.
- Computer programming assignments.
- Art studio.
- Music performance.
- Big term projects.
Also, “good GPA” is commonly 3.0 or higher for passing employers’ initial screening. If there is secondary admission to your desired major at your college, “good GPA” depends on that as well. And if you are pre-med, “good GPA” is probably at least 3.7.