American Semester Systems
There are two main academic calendar systems in the U.S.: the semester system and the quarter system. If you need to convert credits between the two, one quarter credit is equivalent to two-thirds of a semester credit.
Semester System
The semester system is the most common, dividing the academic year into spring and fall terms. In a traditional semester system, the nine-month academic year is split into two 16-week semesters, though some schools offer 18-week semesters. Each semester typically includes about fifteen weeks of instruction and one week of final exams. The first semester starts in late August, often with an orientation week for new students, and ends in mid-to-late December. The second semester begins in early January and ends in late May. After the regular semesters, students can also take optional summer courses (Summer session).
Credits in the semester system are calculated as semester credits: one hour of class per week equals one semester credit. A typical course meeting three hours per week yields three credits. At semester-based schools, students usually need 120–128 semester credits to graduate.
Quarter System
Many West Coast universities use the quarter system. This divides the year into four quarters—fall, winter, spring, and summer—with four start dates (March for spring, June for summer, September for fall, January for winter). Each quarter lasts only about two and a half months, making courses very intensive. One hour of class per week earns one quarter credit. Students typically take 14–18 quarter credits per quarter, and 180–192 quarter credits are required for graduation. Because each quarter is short, exams come frequently (midterms after just a month, and finals a month after that), so students must hit the ground running and handle sustained pressure.
Stanford University, ranked #5 in the latest U.S. News national university rankings, uses the quarter system. The university requires students to attend fall, winter, and spring quarters, with summer being optional.
Credits and Course Selection
A key difference from Chinese universities is that in the U.S., even required courses offer choices—not all students in the same year must take the exact same class. Students can tailor their course loads to their abilities.
Because of this, American universities don’t have the concept of a fixed “class.” Even students in the same year and major may take entirely different courses each semester, and some might not meet until graduation. While unlikely, it does happen.
Credits
Credits for different courses are generally based on class hours. Typically, one credit corresponds to 16 hours of face-to-face time with the professor per semester. For example, a 3-credit course means 48 hours of instruction. In a 16-week semester, that’s one 3-hour class per week, or two 1.5-hour classes.
Schools set maximum and minimum credit limits depending on program length.
A four-year bachelor’s degree typically requires 120–128 credits. Generally, an undergraduate degree takes four years and 120–180 credits; a master’s degree takes about two years and roughly 40 credits; many schools offer five-year combined bachelor’s/master’s programs. One course can be 1–4 credits, and students usually take 3–5 courses per semester, totaling 9–15 credits. Full-time undergraduates must take at least 12 credits per semester; graduate students need at least 9. U.S. requirements mandate at least two semesters per year, so undergraduates need a minimum of 24 credits annually, and graduate students 18. As long as you complete the required credits and pass the exams, you can graduate. However, since schools charge by the credit, graduating early won’t save on tuition.
Course Numbers
A course number is a code for a class, typically up to four letters followed by three or four digits.
The letters indicate the department or course category—e.g., MATH for mathematics, CS for computer science, PSYC for psychology.
The first digit shows the student level: 1 for freshmen, 3 for juniors, 5 and above for graduate courses.
The second and sometimes third digits indicate subcategories, with lower numbers for general education and higher for specialized courses.
From an academic planning perspective, some courses require prerequisites (foundation courses) before you can enroll.
Course Selection Rules at U.S. Universities
For course selection, most schools provide each incoming student with a course catalog that details the credits needed for graduation, requirements for mandatory and elective courses, and course descriptions. Note that some courses are only offered in the spring or fall, so you must plan your schedule and graduation timeline carefully. The last thing you want is to discover in your final semester that a required course is unavailable, delaying graduation. Don’t underestimate this—some students have indeed had their graduation postponed because of poor planning.
Each semester, your academic department also publishes a list of available and recommended courses from which you can choose.
On Dropping/Withdrawing from Courses
There are two ways to drop a course: “Drop” and “Withdrawal.” Drop is usually used during the add/drop period at the start of the semester, while withdrawal occurs later, near the end of the term.
U.S. universities generally allow a one-week shopping period. If you find a course isn’t a good fit—due to teaching style, workload, or other issues—you can drop it and add another. As long as it’s within the school’s deadline, you can freely add or drop courses.
Withdrawal is an opportunity to drop a course later in the semester for various reasons, but only during a specific window, and it won’t appear on your final transcript. This window usually falls one or two weeks before finals week; once the deadline passes, you must take the exam. However, dropping a course must keep you above the required minimum credits for the semester. Some departments or schools don’t allow course withdrawals. Be sure to consult your advisor beforehand and follow their guidance.
Transferring AP Credits
This applies to students who attended high school in the U.S.
AP stands for Advanced Placement, college-level courses offered in high school by the College Board. High school students can take these courses, sit for AP exams, and earn college credits with a qualifying score. While a college course can cost thousands of dollars, an AP exam only costs $82, making it a way to both demonstrate ability and save money.
AP exams are scored on a 5-point scale. A few schools accept scores of 3 or above, while top universities often require 4s or 5s, and some don’t accept AP credits at all. Be sure to check with the specific department.
How to Choose the Right Courses
Make sure you have enough credits
Before picking any fun electives, ensure you’re taking enough credits to stay on track. This is your first priority. As an international student, you must enroll in at least 12 credits per semester to maintain your visa status.
Prioritize major requirements
The courses required for your degree should be your main focus; completing them is the foundation for graduation. Major requirements usually form a significant part of your program, though the exact number varies by school and college. That’s why it’s crucial to consult your advisor or academic counselor and plan your schedule under their guidance.
If you can’t reach your advisor, you can look up your major requirements in your university’s catalog, which typically lists most of your required courses and their timelines. If anything is unclear, email the relevant department to clarify.
One key point: many major courses are sequential, meaning you may need to meet prerequisites before advancing. Also, some courses aren’t offered every year. For instance, an introductory math course might only be available in the fall; if you miss it, you can’t take the next level, potentially waiting a full year—which could delay graduation.
Think about elective courses
Electives are typically chosen based on personal interest. Usually, they have no major-specific prerequisites and can be from any field outside your major. They’re designed to let you explore what you enjoy, giving you more chances to learn about different areas.
Moreover, electives can help you find the right direction. Many international students aren’t sure what they really want to study before declaring a major—electives give them a chance to discover their true interests and aptitudes.
Thus, it’s advisable for international students to avoid taking only major courses and try some challenging courses outside their comfort zone.
Will the course and professor suit me?
Many courses look great on paper but aren’t what they seem. Before enrolling, you must understand the course content and what’s required to earn the credits, then honestly assess whether you can handle it. Not knowing the real workload can lead to two main problems: redundant courses or an overly heavy burden.
Make good use of the shopping period to attend classes and try them out. Don’t skip the first week—go to every class you registered for so you can drop any that don’t fit before the deadline.
Is the course right for me?
Since standard course descriptions are often brief, to get detailed information, you should go to the department office and ask the professor, their TA, or the department secretary directly. Also request the syllabus, which outlines the course objectives, weekly schedule, grading criteria, and reading list—this is the most practical reference for course selection. Pay close attention to the grading breakdown. If a course requires many essays and group presentations and your English writing and speaking skills aren’t strong yet, it might be better to choose a course graded primarily through exams.
Is the professor right for me?
I recommend checking Ratemyprofessor.com to see feedback on the instructor’s teaching style, workload, and grading. Sometimes a course’s title and content sound fascinating, but if you find out the professor is a “killer”—with tons of exams, heavy workload, and low grades—you might want to reconsider. Killers generally aren’t popular with students. Of course, if you’re academically ambitious, you can focus more on the professor’s expertise and perspectives.
Below is a professor rating from SBU, where students leave anonymous reviews, so they tend to be honest. A score of 3.9 is quite high, showing this professor is well-liked!
Look into honors programs
Many schools have honors programs that require you to take specific courses. So if you’re interested, research those requirements early to avoid missing out.
TIPS
Course selection is a critical part of your college journey. If you don’t plan well or pick unsuitable courses, you might only realize it at the end of the semester—and by then it’s too late to fix.
Here, CheersYou（清柚教育） summarizes some course selection tips.
Log into the registration system at the first possible moment, yet somehow someone always beats you.
Read the course selection guide carefully. As mentioned, each department provides a detailed guide. Read it thoroughly. If you don’t even understand the rules before enrolling, you might end up missing or duplicating courses in your final semester, delaying graduation.
Ask your department if you have questions. Unlike in China, where students rarely visit departmental offices for advice, in the U.S., these offices have limited hours and often have lines of students waiting to see advisors for course selection help. You can get very professional guidance and planning there, so don’t hesitate—course selection is crucial for timely graduation.
Upperclassmen (both in your major and outside it—especially useful for electives in other departments) are invaluable resources. From them, you can get firsthand insights into professors’ styles, course difficulty, workloads, and how courses connect. For humanities and social science courses, the professor matters more than the course title. Teaching methods matter more than grading schemes, and clear grading policies are more important than easy grading. Try not to cluster only with other Chinese students.
When you first start, choose foundational courses to build a strong base. Even American students need an adjustment period in their first semester, let alone international students from a different culture and education system. U.S. universities take grades seriously; every course affects your GPA. Blindly enrolling in a course that’s too tough and earning a poor grade can drag down your GPA, hurt your confidence, and—if you can’t recover your GPA—harm your future graduate school applications.
Balance your science and humanities courses. Many private universities don’t require you to declare a major in the first two years. Even if you plan to major in STEM, mix in humanities and social sciences early on. An overload of math and science courses (with their labs and problem sets) can be heavy, while humanities courses improve reading and writing skills—critical for international students.
Register for courses as early as possible. While course registration isn’t as competitive as in China, popular and interesting classes can still fill up quickly. Whether you get in often depends on luck. Each semester, registration windows open at different times depending on your class standing—students closer to graduation get earlier slots to ensure they can get required courses. Before registration, check your university portal for your exact time, so you can log in the moment it opens. When you enter the course number, you’ll see if it’s full. If it is, sometimes there’s a waitlist. You can add yourself to the waitlist, and if someone drops, the next person on the list gets in. Your waitlist position tells you how many are ahead of you. If you haven’t gotten in two days before the add/drop deadline, CheersYou（清柚教育） reminds you to have backup courses ready and switch immediately if needed!
Most Popular Courses Among American College Students
Psychology
History
Biology
English
Abnormal Psychology
Sociology
Calculus
Chemistry
Economics
Philosophy
Most Disliked Courses Among American College Students
Calculus
Biology
Chemistry
English
Statistics
Algebra
Physics
History
Spanish
Psychology
Most Time-Consuming and Disliked Courses
Accounting
Statistics
Algebra
Chemistry
Economics
Calculus
Biology
Organic Chemistry
Physics
Psychology
Most Time-Consuming but Liked Courses
English Literature
Business
Psychology
Statistics, Calculus (tie)
Abnormal Psychology
Sociology, Chemistry and Economics (tie)
Philosophy
Astronomy, Physics and Creative Writing (tie)
Accounting
History
