Credit hours are typically awarded based on the number of contact hours per week over the course of a semester. For example, a three-credit course might meet for three hours per week for 15 weeks. Some courses may also require additional time outside of class, such as for readings, assignments, or lab work.
The total number of credit hours required for a degree can also vary depending on individual transfer credits and other requirements. For example, a student who transfers in credits from another institution may be able to reduce the number of credit hours needed to complete their degree. Additionally, some programs may have additional requirements, such as internships, research projects, or comprehensive exams, that may or may not factor into the total number of credit hours needed.
To determine the exact number of credit hours needed for a specific degree, it's important to consult the academic catalog or program website of the institution in question.