About the Credit Hour Calculator
This credit hour calculator converts the time a course meets into US credit hours using the federal credit-hour definition in 34 CFR 600.2 (the traditional Carnegie model): one semester credit hour reasonably approximates one hour of classroom instruction plus two hours of out-of-class work each week for about fifteen weeks. Enter lecture and lab minutes per week and the term length, and it returns the credit hours, total contact hours and the study time you should plan around.
It is useful for instructors and curriculum committees designing a new course, for students checking how much homework a 15-credit load really implies, and for anyone comparing semester, quarter and accelerated summer terms. A class-hour is the traditional 50-minute period, so a course meeting three times a week for 50 minutes over 15 weeks totals 2,250 minutes — 3 semester credits.
Institutions set their own credit policies within this federal floor, so labs, studios and internships often use a different ratio (two or three lab hours per credit). The defaults — 750 instructional minutes per semester credit, 500 per quarter credit and two study hours per class hour — are common practice; adjust them to match your college catalog.
With the default inputs, the credit hours is 3. Change any value above to recalculate instantly.
How to use the credit hour calculator
- 1Choose semester, quarter or a custom minutes-per-credit value.
- 2Enter lecture minutes per week (for example 3 × 50 = 150).
- 3Add weekly lab or studio minutes and your college’s lab ratio.
- 4Enter the number of weeks of instruction.
- 5Read the credit hours and the weekly study time to budget for.
Formula and method
US federal regulations (34 CFR 600.2) define a credit hour as reasonably approximating at least one hour of classroom instruction and two hours of out-of-class work each week for about fifteen weeks for a semester hour, or ten to twelve weeks for a quarter hour. Because a class "hour" is a 50-minute period, colleges commonly translate this into 750 instructional minutes per semester credit and 500 per quarter credit.
Lab and studio time is divided by the lab ratio before counting, so with a ratio of 3, three hours of lab equal one class hour. Out-of-class work assumes the study ratio (default 2) hours for every 50-minute class hour credited, so one semester credit implies 15 class hours plus 30 study hours over the term. Workload per week divides the totals by the number of weeks, which is why short summer terms feel so intense.
- minutes per credit
- 750 (semester), 500 (quarter) or your institution’s value
- lab ratio
- Lab minutes that count as one class minute
- study ratio
- Out-of-class hours per class hour
Worked examples
Three 50-minute classes a week for 15 weeks
150 minutes × 15 weeks = 2,250 minutes, and 2,250 ÷ 750 = 3 semester credits. At two study hours per class hour that is 90 hours of homework (6 per week), for a total workload of 127.5 hours.
Lecture plus a three-hour lab
The 150-minute weekly lab counts as 150 ÷ 3 = 50 class minutes, so the course earns (150 + 50) × 15 ÷ 750 = 4 credits. Contact time doubles to 75 hours because lab minutes still happen in the room.
Quarter course meeting 200 minutes a week
200 minutes × 10 weeks = 2,000 minutes, and 2,000 ÷ 500 = 4 quarter credits. Out-of-class work is 4 × 2 × 10 = 80 hours, or 8 hours per week on top of 3.3 hours in class.
Frequently asked questions
How many hours is one credit hour?+
A semester credit hour traditionally means one 50-minute class hour per week for about 15 weeks — 750 minutes — plus about two hours of homework for every class hour, so roughly 45 hours of total work per credit.
How many hours a week is a 3-credit class?+
About 2.5 hours in class (three 50-minute periods) and about 6 hours of out-of-class work each week in a 15-week semester, for roughly 8.5 hours in total.
How do quarter credits compare to semester credits?+
A quarter term is about 10 weeks, so a quarter credit is about two-thirds of a semester credit. Transfer offices usually multiply quarter hours by 0.67 (or 2/3) to get semester hours.
How are lab credit hours calculated?+
Labs usually earn less credit per hour because they involve less outside work. Many colleges award one credit for two or three hours of lab each week; set the lab ratio to match your catalog.
Is 15 credit hours a full-time load?+
Twelve credits per semester is usually the minimum full-time load for financial aid, but 15 credits a semester (30 a year) keeps you on track to finish a 120-credit bachelor’s degree in four years.