Every college has a standard process for calculating tuition and determining how much academic credit should apply to each course. A common way of doing this is with a standard unit called a college credit hour.
USA Education Guides defines a credit hour as a numeric unit of study at an institution of higher learning.
Measured by classroom hours
The number of credit hours for a course is directly correlated with the number of hours students spend in class each week. Classes that meet for four hours per week are usually considered four-credit-hour courses.
Courses in which students earn fewer credit hours may have less demanding homework loads. For instance, most traditional college students are required to take a one-credit-hour survey course during their first semester. This course is not as difficult as the three- and four-hour courses they will take.
Credit hours are used to determine course costs. For instance, a college that charges $50 per credit hour will bill the student $100 for a two credit-hour course.
Most degree programs require students to complete a certain number of credit hours focused in their area of study before a degree is conferred. For instance, an English major may need to complete 50 credit hours in English before he can graduate.