To ensure that all students at a college complete the same course load for a particular degree program, colleges will often set a requirement of hours that each student needs to meet before being eligible to apply for graduation. These are often called credit hours, and usually correspond to the number of hours that are spent in the classroom each week per class.
Add up the number of hours you attend formal lectures or spend in a laboratory each week. Only include the number of hours that are mandatory. If a class meets for 4 hours a week, but gives an optional study period for an hour on Fridays, this optional study period would not be included. If your college has 50 minute lectures, count these as one hour. Note also that laboratory classes often require significantly more hours of time investment than credits given. Use this method as a rough estimate of your credit hours.
Review your official class schedule to see how many hours of lecture and laboratory are officially mandated for your courses. Add the hours for which you are expected to be in class only, not unofficial tutoring sessions.
Check the registration materials you received from the Registrar's office after choosing your courses for the semester. It will have the credit hours for each course listed in the course details.
Consult your college's academic handbook to see how many credit hours each course is worth per semester. Make sure you are using the most current edition of the book as some courses do change over time. Some colleges list their most recent version of the academic handbook on the Registrar's web page.