What Are IB Classes?

An IB class usually refers to the subjects taken as part of the IB Diploma Programme (DP). Every DP student takes six subjects, one from each of six subject groups, alongside three core requirements, Theory of Knowledge, the Extended Essay, and Creativity, Activity, Service (CAS). This structure is what forces the breadth the IB is known for: a DP student can't specialize in only science or only humanities the way students in some other systems can.

The Six IB Diploma Subject Groups

Students choose one subject from each of the following groups:

Math Track Split: Math AA vs. Math AI

Within Group 5 (Mathematics), students must choose between two distinct pathways: Analysis & Approaches (AA) or Applications & Interpretation (AI). Math AA focuses heavily on abstract algebra, calculus, and mathematical proofs, making it the essential choice for students targeting STEM, Engineering, Computer Science, Physics, or competitive Economics degrees. On the other hand, Math AI emphasizes statistics, data modeling, and practical problem-solving using graphing calculators. This track is designed for students pursuing Social Sciences, Medicine, Psychology, Business, or the Humanities, where practical data analysis is more relevant than pure abstract calculus.

Higher Level (HL) vs Standard Level (SL)

Within those six subjects, students take three or four at Higher Level (HL) and the rest at Standard Level (SL). HL subjects involve roughly 240 teaching hours and go deeper into the content; SL subjects involve roughly 150 teaching hours and cover a narrower scope. The split lets students go deep in the areas that matter most for their university plans while still meeting the IB's breadth requirement everywhere else.

How IB Classes Are Assessed (IA vs. EA)

Unlike traditional high school courses that rely almost entirely on final exams, every IB subject combines both internal and external evaluations to determine a student's final score from 1 to 7. Internal Assessments (IAs) are subject-specific research projects, lab reports, oral commentaries, or portfolios completed during class time. These are graded by the student's own teacher, moderated externally by the IBO, and typically account for 20% to 30% of the overall subject grade. The remaining portion of the grade comes from External Assessments (EAs), which are standardized written exams taken at the end of the two-year programme and graded by official IB examiners worldwide.

The DP Core What Ties It All Together

Theory of Knowledge (TOK)

A course that asks students to examine how we know what we know, comparing ways of knowing like reason, emotion, and perception across different areas of knowledge like the natural sciences, history and the arts assessed through an essay and an exhibition.

Extended Essay (EE)

An independent, 4,000-word research paper on a topic of the student's choosing, usually connected to one of their six subjects. It's the closest thing most DP students will do to a university-style research project before actually reaching university.

Creativity, Activity, Service (CAS)

A non-academic requirement built around real-world experience creative pursuits, physical activity, and service to others completed over the two years of the DP rather than assessed with a grade.

How Students Choose Their IB Classes

• Match HL choices to intended university majors, many degree programmes list specific HL subject requirements
• Play to genuine strengths at HL, since those subjects carry more depth and workload
• Balance the overall workload, three HL sciences plus HL Math, for example, is a heavier combination than mixing HL humanities with SL sciences
• Check language requirements early, since Group 1 and Group 2 subjects depend on a student's existing language background
• Talk to a school counselor about how a subject combination lines up with specific university or country requirements

Example IB Subject Combination

A student planning to study Economics at university might choose:

• English A (HL)
• Spanish B (SL)
• Economics (HL)
• Chemistry (SL)
• Mathematics: Analysis & Approaches (HL)
• Visual Arts (SL)

That's three HL subjects (English, Economics and Math) and three SL subjects, a common, and balanced pattern.

Related Reading

• What Is the IB? A Complete Guide to the International Baccalaureate
• What Is an IB School? How schools become authorized IB World Schools, and how to evaluate one.

Frequently Asked Questions

Can I choose any six subjects I want?

Not entirely, you must take one subject from each of Groups 1 to 5, and either a Group 6 Arts subject or a second subject from Groups 1 to 5. Course availability also depends on what your specific school offers.

Do I need to study a foreign language?

Yes, in almost all cases. Group 2 (Language Acquisition) requires learning a language that isn't your strongest, though the level (from AB initio to HL) depends on prior experience.

What happens if I want to drop a subject partway through?

This is possible but requires school and, in some cases, IBO approval, and it can affect your ability to meet diploma requirements, it's worth discussing with a coordinator before making changes.

How many total classes does the IB Diploma involve?

Six subjects plus the three core components (TOK, EE, CAS) so effectively six academic courses running alongside the core requirements over two years.

Choosing your IB subjects? Baccalytics has free mock exams and practice questions across most DP subjects, so you can test-drive a subject's difficulty before committing to it at HL, browse by subject on our Mock Exams page.