How to Choose Your IB Subjects: A Complete Guide

Future surgeon, engineer, lawyer, or still deciding? The six IB subjects you pick on your grade 10 course form are where that future starts to take shape, and every combination follows the same structure.

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The rules are simple: take one course from each of Groups 1 to 5, plus an arts course or another Group 1-4 subject. Most students put three at Higher Level and three at Standard Level.

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In this guide, we’ll walk you through a seven-step method, from your school’s course list to a final check with your IB coordinator, including how HL choices affect your diploma and US college credit.

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Let’s start with the rules every combination has to follow.

Key takeaways

• Every IB student takes six subjects across six groups: studies in language and literature, language acquisition, individuals and societies, sciences, mathematics, and the arts. The arts slot can be swapped for a second science, humanity, or language.
• HL subjects run for 240 teaching hours over two years, compared with 150 at SL. To earn the diploma, you need 24 points overall, including 12 across your HLs and 9 across your SLs.
• Choosing your IB subjects takes seven steps: check your school’s course list, shortlist majors, research requirements, assess your strengths, pick your math course, set your HLs, and stress-test with your IB coordinator.
• US colleges rarely require specific HLs but do read rigor, while UK universities name HL grades in their offers. Imperial College London’s typical Mechanical Engineering offer, for example, is 40 points with 7s in HL Physics and Math.
• Common mistakes include ignoring timetable blocks, copying friends, overlooking requirements abroad, picking Math AI when a program needs AA, choosing HLs for prestige, and waiting too long to switch levels or subjects.
• If you’re undecided, take Math AA plus one science and one humanity at HL to keep several majors within reach. Whatever you choose, a hard subject tied to your degree can outweigh a 7 in an unrelated one.

How IB subject choice works

The clearest way to picture your choices is six slots, one for each subject group. Five slots are fixed: studies in language and literature, language acquisition, individuals and societies, sciences, and mathematics.

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The sixth slot belongs to the arts, such as Visual Arts, Music, Theatre, or Film. You can fill it with a second science, individuals and societies, or language course instead. Math can’t take that slot, so only one math course counts toward your diploma.

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Interdisciplinary courses give you even more room to plan. Environmental Systems and Societies (ESS), for example, meets two group requirements in one course. Although it covers Group 3 and Group 4, ESS earns one grade. A 7 in ESS isn’t a 7 in Group 3 plus a 7 in Group 4.

The six IB subject groups at a glance

Your IB classes come from six subject groups, though the exact list depends on what your school offers.

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Here are the different groups and what each one covers:

• Group 1: Studies in language and literature. You study your best language, usually English, in either Language A: Literature or Language A: Language and Literature. Literature focuses on novels, poetry, and plays, while Language and Literature adds texts like speeches and ads.
• Group 2: Language acquisition. Learning an additional language here means using it for real, from everyday conversations to debating current issues. Language B suits students with some prior study, while ab initio is a beginner course offered at SL only.
• Group 3: Individuals and societies. How do people, markets, and societies work? Courses like Business Management, Economics, History, and Psychology explore that question through reading, debate, and evidence-based writing.
• Group 4: Sciences. Practical work sits at the heart of every science course, ending with an investigation you design yourself. Alongside Biology, Chemistry, and Physics, you’ll find Computer Science and Design Technology.
• Group 5: Mathematics. Every diploma student takes one math course: Analysis and Approaches (AA) or Applications and Interpretation (AI). AA leans toward pure math, while AI focuses on real-world data.
• Group 6: The arts. Visual Arts, Music, Theatre, Dance, and Film are assessed on what you create, from portfolios to performances. You can also swap this slot for another subject.

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Each school offers its own selection within these groups, so check your course list before you plan. For a closer look at each course, explore our IB Preparation blogs.

Higher Level vs Standard Level

Most IB subjects run at Higher Level (HL) or Standard Level (SL), with HL adding 90 extra teaching hours.

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Here’s a closer look at the difference between SL and HL:

How to choose your IB subjects in 7 steps

To choose your IB subjects, you should match your school’s options to your strengths, preferred assessment style, and likely majors.

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In the next sections, we’ll guide you through each step, from shortlisting majors to picking your HL subjects.

Step 1: Get your school’s course list and timetable

Your school’s offer sets the limits for everything else, so start there. Ask your IB coordinator for this year’s course list, which subjects run at HL, and how the timetable blocks work.

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Timetable blocks decide which subjects you can combine. If Physics HL and Economics HL share a block at your school, you can’t take both, however well they fit your plans.

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Check two more details before you plan. Courses with low sign-ups may not run, and some languages appear only as ab initio. If a subject you need is missing, ask whether your school offers IB-authorized online courses.

Step 2: Shortlist two or three possible majors

Name two or three directions instead of committing to one, such as pre-med, engineering, and economics. A shortlist keeps several paths open while you’re still discovering what you enjoy most.

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If you’re unsure where to start, use these three prompts:

• Favorite classes: Which subjects do you look forward to, even on a busy week?
• Activities you’d do for free: Think of clubs, projects, or reading you choose when nobody is grading you.
• Careers you’ve explored: List jobs you’ve shadowed, researched, or asked someone about directly.

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Then look for overlap. If biology, hospital volunteering, and a talk with a nurse all point to health, add pre-med.

Step 3: Research what those majors expect

Look up four or five realistic colleges for each shortlisted major, then compare what their admissions pages recommend.

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US colleges rarely require specific HL subjects, but they do read rigor. MIT, for example, recommends calculus, physics, chemistry, and biology without requiring any specific courses.

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UK universities write offers around named HL grades. Imperial College London’s typical offer for Mechanical Engineering is 40 points with 7s in HL Physics and Math. If you might apply abroad, check these early.

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You’ll also see IB listed alongside AP. Neither is objectively harder, because AP tests single courses while IB grades a connected two-year program. Still, the full diploma is usually more demanding, combining six subjects with TOK, the EE, and CAS.

Step 4: Assess your strengths and preferred assessment style

While we mentioned that favorite classes narrow your options, you need to pair them with your grades and teacher feedback to confirm where you’ll score well. A subject you love but score 4s in is a risky HL choice. Check your grade 9 and 10 results, test scores, and teacher feedback to see where you consistently perform well. 

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Next, decide how you work best. Some students shine in timed exams, while others do their best work through longer projects and portfolios.

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This matters because the IB balances exams and coursework differently by subject. Internal assessment makes up 20% of your grade in Biology and both math courses, but 40% in Design Technology.

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If you’re unsure about a class, read its IB subject brief or ask the teacher for a course outline. Each short brief shows how the course is assessed.

Step 5: Pick your math course: AA or AI

Every diploma student takes one math course, so this choice applies to everyone. In a nutshell, pick Math AA for STEM-heavy shortlists and Math AI for social sciences or business.

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Here’s a closer look at how the two courses compare:

• Math Analysis and Approaches (AA): It covers algebra, calculus, and proof. The course suits engineering, computer science, and economics, leading to roles like software engineer or actuary.
• Math Applications and Interpretation (AI): Statistics and modeling with real-world data sit at its core. The course suits psychology, biology, and business, leading to market research or public health careers.

Step 6: Choose your HL and SL subjects

Your HL subjects carry the most weight, so choose them first and fill the remaining groups at SL. Aim for HLs that your shortlisted majors need, your grades support, and you’ll enjoy for 240 hours.

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Here’s an example for a typical engineering student:

• Higher Level (HL): Engineering programs look for strong math and physics, so Math AA and Physics are natural HL picks. Chemistry can take the arts slot as a second science. Strong HL scores can also earn college credit at many US schools.
• Standard Level (SL): At 150 hours each, options like English A: Literature, Spanish B, and Economics could cover Groups 1 to 3. This mix keeps the program broad without overloading the schedule.

Step 7: Stress-test your combination with your IB coordinator

Before submitting, run three checks with your IB coordinator.

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First, confirm the diploma conditions. You need 24 points overall, 12 across your HLs, and 9 across your SLs, with no grade 1 and no more than two grade 2s.

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Next, check your workload. Three essay-heavy HLs, like History, English, and Economics, can pile long writing tasks into Year 2. Three lab sciences do the same with investigations.

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Finally, choose your Extended Essay subject. The 4,000-word EE usually works best in one of your HLs, where you know the content well.

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To plan your research question early, explore our IB Extended Essay guide for word count rules, topic ideas, and examples.

Best IB subject combinations by major

The combinations below build HLs around a likely major, following the same logic as the IB’s own example subject choices.

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Here are recommended HL and SL picks for popular majors, though each college sets its own expectations:

What if you don’t know your major yet?

Most advice, including the steps above, assumes you already have a major in mind. But if you haven’t chosen one yet, don’t worry. You’re not alone, and many grade 10 students are still exploring their options while choosing their IB subjects.

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Start with Math AA at SL or HL, then take one science and one humanity at HL. For your third HL, pick your strongest subject, such as English A: Literature or Economics.

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Together, these choices keep STEM, pre-med, and humanities majors within reach. To narrow things down, test a subject through summer study or an independent project. A few weeks of real work often reveals more than a year of guessing.

The hardest IB classes: should you avoid them?

There’s no official ranking of the hardest IB classes. Difficulty depends on how you measure it, whether by grades, workload, or your own strengths, so it shouldn’t decide your choices alone.

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Here are the five most commonly cited, and why each one is demanding:

• Physics HL: Abstract ideas, like electromagnetic induction and quantum physics, have to be worked through using demanding math.
• Math AA HL: Every topic builds on the last, so small gaps grow quickly. HL also adds a third exam paper of extended, unfamiliar problems.
• Chemistry HL: Recall alone won’t carry you, because the large syllabus mixes memorized content with multi-step calculations.
• Biology HL: Sheer volume is the challenge, with detailed processes to learn and long written answers to explain them.
• English A: Literature HL: No single right answer exists, and top marks depend on original interpretations of complex texts. HL also adds a coursework essay.

Common mistakes to avoid when choosing IB subjects

Most subject-choice problems come from a few avoidable mistakes, and spotting them early saves a stressful switch later.

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Here are some of the most common ones to watch for:

• Ignoring timetable blocks: Two subjects in the same block can’t run together, however well they fit your plans.
• Copying your friends: Their majors, strengths, and timetables differ from yours, so the same combination rarely fits.
• Overlooking requirements abroad: UK offers name specific HLs, so skipping Physics HL can rule out engineering at Imperial College London.
• Picking Math AI when you need AA: Many engineering and physics programs prefer AA, and switching later gets harder each week.
• Choosing HLs for prestige: Three tough HLs look impressive, but low scores can put your 12-point HL minimum at risk.
• Waiting too long to switch: Dropping from HL to SL is usually possible during Year 1, but moving up from SL gets harder as HL-only content builds.
• Missing switching deadlines: Full subject changes, including between Math AA and AI, work best in the first few weeks, with cutoffs set by school policy and IB registration.

Explore subjects before you choose with Immerse Education

Many IB subjects, like Economics, Psychology, and Philosophy, rarely appear on grade 9 or 10 timetables. That means you could commit 240 hours to an HL you’ve never studied. A Pre-University Summer School can help you test a subject first.

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It gives ages 13 to 18 two weeks of university-level study in Oxford, Cambridge, Toronto, and more. Choose from over 20 subjects, from Medicine and Law to Economics and Psychology.

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If you’re weighing careers, our Career Insights summer school places ages 15 to 18 with industry professionals in London, New York, or Tokyo, where site visits show what the work involves day to day.

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Prefer to learn from home? Our Online Research pathway pairs you 1:1 with an Oxford, Cambridge, or Ivy League tutor to build a research paper.

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Whichever pathway you choose, you’ll return with clearer subject choices and real evidence of interest for your college applications.

FAQs

How many IB subjects do you take?

You take six IB subjects, one from each of Groups 1 to 5, plus an arts course or a second subject. Most students study three at Higher Level and three at Standard Level.

What if my school doesn’t offer the subject I want?

Ask your IB coordinator whether an IB-authorized online course is available. If not, choose the closest subject your school offers and explore your preferred one through summer study or independent research.

Should I take Math AA or Math AI?

Choose Math AA if your shortlist includes engineering, computer science, physics, or economics. Choose Math AI for psychology, biology, or business. If any program you’re considering names AA, take AA.

What are the 5 hardest IB subjects?

Physics HL, Math AA HL, Chemistry HL, Biology HL, and English A: Literature HL are the five most commonly cited. Difficulty still depends on whether you measure it by grades, workload, or personal strengths.

Do US colleges care which IB subjects you take?

Yes, US colleges read the rigor of your IB subjects, even if few require specific HLs. MIT, for example, recommends calculus, physics, chemistry, and biology, so choose HLs that show readiness for your major.

Is IB more difficult than AP?

Neither is objectively harder, because AP tests single courses while IB grades a connected two-year program. The full IB diploma is usually more demanding overall, combining six subjects with TOK, the EE, and CAS.

Conclusion: making your IB subject choices with confidence

Choosing your IB subjects takes seven steps, from checking your school’s options and shortlisting majors to setting your HLs and stress-testing the final combination.

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Remember that the right combination isn’t the one that looks hardest. It’s the one you can score well in that keeps your shortlisted majors open.

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For subject-specific next steps, from Biology to Business Management, explore our IB Preparation blogs, which break down each course’s content and assessment.

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Still unsure about an HL? Try it first at one of our Immerse Education Summer Schools, and walk into grade 11 knowing your choice fits your future.