Semester hours and quarter hours are both college credit hours, but they come from calendars of different lengths, so a quarter hour is worth two-thirds of a semester hour. Under federal rules a semester (or trimester) hour must include at least 30 clock hours of instruction and a quarter hour at least 20, which is the 3-to-2 ratio behind every conversion: multiply quarter hours by 2/3 to get semester hours, or semester hours by 1.5 to get quarter hours.
The difference matters most when you transfer between a quarter-system school and a semester-system school, or when a job or licensing board states its requirement in one unit and your transcript uses the other.
Semester Hours vs Quarter Hours at a Glance
| Feature | Semester hours | Quarter hours |
|---|---|---|
| Calendar | Two main terms of about 15 weeks | Three main terms of 10 to 12 weeks (plus summer) |
| Federal minimum instruction per credit | 30 clock hours | 20 clock hours |
| Weekly work per credit (Federal Student Aid definition) | 1 hour in class plus 2 hours out of class, for about 15 weeks | 1 hour in class plus 2 hours out of class, for 10 to 12 weeks |
| Conversion | 1 semester hour = 1.5 quarter hours | 1 quarter hour = 2/3 semester hour |
| Typical full-time load | 15 credit hours per semester, 30 per year | The equivalent of 15 semester hours per term, expressed in quarter hours |
What Is a Semester Hour?
A semester hour, or semester credit hour, is the credit unit used by schools whose academic year has two long terms. The Federal Student Aid Handbook defines a credit hour as work that reasonably approximates not less than one hour of classroom or direct faculty instruction and a minimum of two hours of out-of-class work each week for approximately 15 weeks for one semester or trimester hour of credit. In practice a semester credit hour is 15 to 16 contact hours per term, and a normal full-time load is 15 credit hours per semester or 30 per academic year.
What Is a Quarter Hour?
A quarter hour is the same idea on a quarter calendar, where the year is divided into shorter terms. The same federal definition allows 10 to 12 weeks for one quarter hour of credit, and the Code of Federal Regulations requires a quarter hour to include at least 20 clock hours of instruction, against 30 for a semester hour. Because each term is shorter, a course on the quarter system usually carries more credit hours than the same course on the semester system, and students take more courses per year.
How to Convert Between Them
- Quarter hours to semester hours: multiply by 2/3. A 5-quarter-hour course is three and one-third semester hours; a 180-quarter-hour bachelor’s degree is 120 semester hours.
- Semester hours to quarter hours: multiply by 1.5. A 3-semester-hour course is four and a half quarter hours; a 120-semester-hour degree is 180 quarter hours.
- Rounding: receiving schools often round to the nearest half or whole credit, so a 5-quarter-hour course may transfer as three or three and a half semester hours depending on the school’s policy.
Why People Mix Them Up
- Both are called “credit hours”. Transcripts often just say “hours”, and the calendar system is stated somewhere else on the document.
- The numbers look bigger on a quarter transcript. A student with ninety quarter hours has the same standing as one with sixty semester hours, not more.
- Requirements are written in one unit. Job postings, graduate schools and licensing boards usually state semester hours, so quarter-system graduates have to convert.
Frequently Asked Questions
- Is a quarter hour the same as a semester hour? No. A quarter hour is two-thirds of a semester hour, because a quarter term is shorter.
- How many quarter hours equal 3 semester hours? Four and a half quarter hours.
- How many semester hours is a 180-quarter-hour degree? 120 semester hours.
- Where does the 2/3 ratio come from? From the federal minimums of 30 clock hours per semester hour and 20 per quarter hour: 20 divided by 30 is two-thirds.