IB Diploma: The Ultimate Guide to Getting into Oxford or Cambridge

Applying to Oxford or Cambridge is a dream shared by thousands of bright students across the globe. And while it’s a big goal — no doubt about that — it’s absolutely within reach if you approach it seriously, start early and prepare smart.

The International Baccalaureate (IB) is one of the most reliable routes to the UK’s top universities. Both Oxford and Cambridge highly value the IB Diploma — and so do hundreds of leading institutions worldwide. In this guide, we’ll walk you through how to get the highest possible IB scores, how to pick the right subject combination, and what steps you can take to make your Oxbridge application stand out.

Table of Contents:

1. What is the IB diploma?
2. How to choose subjects for Oxbridge
3. How to maximise your IB score
4. Extracurriculars and CAS
5. Applying to Oxford and Cambridge with an IB diploma
6. Frequently Asked Questions (FAQ)

1. What is the IB Diploma? An Overview of the Programme

The International Baccalaureate Diploma Programme (IBDP) is a two-year pre-university academic programme for students aged 16–19. It is developed by the International Baccalaureate Organization (IBO) and is recognised by universities around the globe—from Harvard to Cambridge.

To be specific, the IB Diploma is currently accepted by over 2,520 universities in 74 countries. Impressive numbers, right?

But the IB Diploma is more than just a rigorous high school curriculum. At its core lies a distinctive mission: "to develop inquiring, knowledgeable and caring young people who help to create a better and more peaceful world through intercultural understanding and respect.” This is the vision stated on the official IBDP website.

What sets the IB apart from most national school systems is its broad academic foundation, alongside a strong emphasis on personal development and key skill sets:

• thinking skills
• research skills
• communication skills
• social skills
• self-management skills

IB graduates are exceptionally well-prepared for success at world-class universities.

Structure of the IB programme

Unlike A-levels (which we cover in detail in this article), the IB requires students to study six subjects simultaneously.

Each IB student selects one subject from each of the following six groups:

1. Language and Literature (e.g., English Literature, Russian A)
2. Language Acquisition (e.g., French B, Spanish ab initio)
3. Individuals and Societies (e.g., History, Economics, Global Politics)
4. Sciences (e.g., Biology, Chemistry, Physics)
5. Mathematics (two options: Mathematics: Analysis and Approaches or Mathematics: Applications and Interpretation)
6. The Arts (e.g., Visual Arts, Theatre) — or an additional subject from groups 1–5

Out of these six subjects, at least three must be taken at Higher Level (HL), while the remaining are at Standard Level (SL). HL subjects are more in-depth and demanding than SL ones and are particularly important for university admissions.

The IB core components

In addition to subject coursework, each IB student must complete three core components:

• Extended Essay (EE) — an independent, research-based paper of up to 4,000 words on a topic of the student’s choice.
• Theory of Knowledge (TOK) — a critical thinking course exploring how we acquire and justify knowledge, assessed through an essay and a presentation.
• Creativity, Activity, Service (CAS) — a programme of extracurricular engagement to foster personal development and community involvement.

These elements help shape the intellectual profile of an IB graduate — someone who asks questions, builds arguments, thinks independently, and is not afraid of complexity.

How is the IB diploma scored?

The maximum possible score is 45 points:

• Each of the 6 subjects is graded out of 7, giving a total of up to 42 points.
• An additional 3 points come from a combined assessment of EE and TOK based on a performance matrix.

To receive the diploma, a student must earn at least 24 points and complete all programme components. However, admission to top-tier universities like Oxford or Cambridge usually requires 38 to 42 points, with scores of 6–7 in HL subjects relevant to the chosen course.

2. How to Choose Subjects for Oxbridge

One of the most critical factors for successful admission is the strategic selection of IB subjects, especially at the Higher Level. Your choices should align with your intended field of study and reflect academic strength.

Choose academically rigorous subjects

Oxford and Cambridge favour applicants who choose rigorous, traditional academic subjects — particularly at HL. These subjects typically require analytical thinking, theoretical grounding, and a solid academic foundation.

Examples of academically preferred HL subjects:

• Mathematics: Analysis and Approaches HL
• Physics HL, Chemistry HL, Biology HL
• English Literature HL
• History HL, Geography HL
• Foreign Languages HL (e.g., French B HL, Latin HL, German HL)

Applied or interdisciplinary subjects like Business Management, Environmental Systems and Societies, or Sports Science are not strictly prohibited — but they’re not generally recommended as core HL subjects for Oxbridge applicants, especially for competitive courses.

Pro tip: Do not cut corners on Mathematics. It is essential for most degree programmes. Choosing the right version is key:

• Mathematics: Analysis and Approaches HL — ideal for maths, engineering, economics, and natural sciences
• Mathematics: Applications and Interpretation HL — generally more suitable for social sciences, architecture, and design, but may not meet requirements for many Oxbridge STEM courses

Match subjects to your target course

Different degree courses have specific subject expectations. Here are a few common examples:

Medicine:

• Required HL subjects: Chemistry HL, Biology HL
• Recommended: Mathematics HL

Economics / PPE (Philosophy, Politics & Economics):

• Required HL subject: Mathematics HL
• Recommended: History HL, Economics HL (if available)

Engineering / Physics:

• Required HL subjects: Mathematics HL, Physics HL
• Recommended: Chemistry HL (especially for chemical engineering)

Language & Literature:

• Required HL subject: English Literature HL
• Recommended: History HL, Foreign Language HL

Computer Science:

• Required HL subjects: Mathematics HL, Physics HL
• Recommended: Computer Science HL (if offered)

Important note: Choosing the right HL subjects is absolutely crucial. If you don’t meet the subject requirements, your application may be rejected automatically — regardless of your overall score.

Oxford vs Cambridge: differences in approach

While Oxford and Cambridge share a similar academic prestige, their teaching philosophies and admissions preferences can differ slightly — and this can influence your subject choices.

1. Cambridge: structured, STEM-focused, and research-heavy

Cambridge is known for its strong theoretical and research-oriented focus, especially in STEM subjects. Their admissions policies reflect this:

• Strict subject requirements: Cambridge clearly outlines required HL subjects. For example, Physics applicants must have both HL Math and HL Physics — no exceptions.
• Mathematics as a baseline skill: Even for non-STEM courses like Economics or Sociology, Cambridge often expects Mathematics: Analysis and Approaches HL.
• Emphasis on academic depth: The university values candidates capable of deep theoretical reasoning and independent study.

2. Oxford: flexibility and interdisciplinarity in the humanities

Oxford, while equally rigorous in sciences, is widely recognised for its strength in interdisciplinary and humanities-based courses like PPE, Philosophy, History, and English. Their approach tends to be:

• Slightly more flexibility in subject choices — particularly for arts and humanities. For example, PPE applicants are not required to have studied Economics, although it helps.
• Focus on argumentation and reasoning. Logic, critical thinking, and essay-writing skills are key, often demonstrated through HL subjects like History or English.
• Strong interest in academic curiosity/ Oxford places value on students who show deep personal interest in their subject — your chosen subjects should reflect that you "think like a scholar" in your field.

3. How to Score Top Marks in the IB

Getting a high score in the International Baccalaureate isn’t easy. The maximum score is 45 points: 42 from academic subjects and up to 3 additional points from the IB core — the Extended Essay (EE), Theory of Knowledge (TOK), and CAS. While CAS (Creativity, Activity, Service) isn’t graded, the other two components can have a real impact on your final score — and potentially on your university application.

Here are three strategies to help you reach your full potential.

Internal Assessments (IA)

Internal Assessments are mini research projects you complete for each subject (with some exceptions in the arts). They typically count for 20–30% of your final grade and are assessed based on research skills, structure, argumentation, and presentation.

How to choose a strong topic:

• Start with the syllabus: make sure your topic fits within the course content. For example, a Math IA should focus on methods you’ve actually studied — not on abstract theory from university-level math.
• Narrow it down. “How does temperature affect plant growth?” is far too broad. Better: “How does a 5°C change in temperature affect the rate of photosynthesis in Elodea canadensis?”
• Avoid clichés. Examiners have read dozens of IAs on how music affects concentration. Even a simple topic can stand out if you bring a fresh angle.

Structure of a successful IA:

• A clear introduction with a focused research question.
• A well-explained methodology that justifies your approach.
• Thoughtful analysis that interprets results, not just presents them.
• A conclusion that answers your question and acknowledges limitations.

Extended Essay (EE)

The Extended Essay is a 4,000-word piece of academic writing based on independent research in a subject of your choice. A strong EE isn’t just a supercharged homework assignment — it’s your chance to show critical thinking, research ability, and academic maturity.

Choosing a subject and topic:

• Pick a subject you're genuinely strong in (not just one you enjoy). Universities often look at how your EE subject lines up with your intended degree.
• Aim for something that goes beyond the syllabus, but not too far — the best topics are both original and realistic.

The EE is graded across five criteria:

A — Focus and Method (6 points)

B — Knowledge and Understanding (6)

C — Critical Thinking (12)

D — Presentation (4)

E — Engagement (6)

A strong essay shows you can take a position and support it with logic, evidence, and structure.

Theory of Knowledge (TOK)

TOK is all about asking: how do we know what we know? It consists of an essay and (optionally) a presentation. It’s worth up to 10 points, but only contributes a maximum of 3 bonus points to your final diploma score — together with the EE.

How to avoid failing:

• Don’t get lost in vague philosophy. Be specific, use real-life examples, and build clear arguments.
• The question must be about knowledge itself — not just about ethics or history. Bad: “Should we clone humans?” Better: “What challenges arise in acquiring knowledge in biology compared to ethics?”

Common pitfalls:

• Going too abstract or rambling off-topic.
• Repeating theory without applying it to real contexts.
• Ignoring the contrast between different Areas of Knowledge.

How to avoid burnout while studying for the IB

The IB is a marathon, not a sprint. Between six subjects, essays, and CAS projects, many students feel overwhelmed. To stay balanced, try these practical tips:

1. Build a realistic schedule that includes downtime. Breaks and weekends aren’t a waste of time — they’re fuel for your productivity.
2. Use the Pomodoro Technique: 25 minutes of focused work, 5 minutes of rest.
3. Shift your priorities during crunch time — the core components (EE, TOK) can give or take away the 3 points that make all the difference.
4. Don’t forget the basics: regular exercise, good nutrition, and enough sleep. It sounds obvious, but high-achieving students often neglect this — and pay the price.

4. Extracurriculars and CAS: How to Strengthen Your Oxbridge Profile

While academic performance is absolutely crucial for getting into Oxbridge, it’s not the whole picture. Admissions tutors also want to see what kind of person you are outside the classroom. The IB Diploma has a built-in opportunity for this: the Creativity, Activity, Service (CAS) component — and it can become a powerful asset in your application.

How CAS can boost your application

At first glance, CAS might seem irrelevant to Oxbridge admissions — it isn’t graded, and it doesn’t show up as a number on your diploma. But don’t underestimate it. In reality:

• Your CAS project can feed directly into your Personal Statement, helping you demonstrate motivation, curiosity, or a passion for your subject.
• CAS supervisors can write meaningful reference letters, especially if they’ve seen you lead a project, solve problems, or take initiative.
• Oxbridge values applicants who take initiative, manage their own time, and show intellectual curiosity beyond the classroom — all things CAS can highlight.

On top of that, CAS helps you develop soft skills that are highly valued at Oxbridge: self-management, social awareness, critical thinking, and collaboration.

Strong CAS projects and volunteering examples 

Oxbridge isn’t expecting every student to launch a nonprofit or build a tech startup. What matters is how your extracurriculars connect to your academic interests — and the depth of your engagement.

Here are some examples of CAS projects that can really stand out, especially when described effectively in your application:

For future Natural Sciences, Medicine, or Engineering students:

• Volunteering at science camps or museums.
• Organizing science outreach events for younger students.
• Environmental projects like local ecosystem clean-ups, paired with scientific research.
• Starting a STEM club or running a lecture series at school.

For humanities applicants (History, Philosophy, Literature, Law):

• Running a blog or podcast on history or literature topics.
• Participating in debate clubs, student newspapers, or Model UN.
• Volunteering in museums, archives, or libraries.
• Creating a book club or discussion group around key texts.

For psychology or sociology applicants:

• Conducting a small-scale behavioral research project through CAS.
• Volunteering with organizations that support people with learning or developmental differences.
• Leading school-wide mental health awareness campaigns.

Universal high-impact ideas:

• Initiating your own projects, rather than just joining existing ones. Oxbridge loves applicants who show leadership.
• Long-term involvement — like developing and launching a mentorship program for younger students.
• Academic crossover — e.g. publishing a booklet based on your Extended Essay or organizing a student research conference.

A list of activities is good — but what really matters is showing why you did them, what you learned, and how they reflect your values and interests. That depth of reflection can make all the difference.

5. Applying to Oxford and Cambridge with an IB Diploma

Let’s be honest — Oxbridge admissions are extremely competitive. To have a real shot, you need to understand exactly what they expect from IB students and how you can meet (or exceed) those expectations.

What IB scores are considered competitive?

Most successful applicants to Oxford or Cambridge receive conditional offers in the range of 38 to 42 points, with 6s and 7s at Higher Level (HL) in relevant subjects. For certain courses, the requirements are even more specific.

For example:

• For Computer Science at Cambridge, you might need 40–42 points, including 776 at HL, with top marks in maths.
• For Law at Oxford, expect at least 38 points, with a 6 or 7 in history or other relevant subjects.

Oxbridge isn’t just looking for high grades — they want to see top performance in the right subjects, especially at HL.

Why predicted grades matter so much

When you apply through UCAS, your school submits predicted grades — an estimate of what you’re expected to achieve in your final exams. These predictions play a huge role: they determine whether or not you get invited to the interview stage.

Even if you end up with perfect final results, weak predictions can block your chances early on.

Here’s the nuance: predicted grades don’t have to be identical to your most recent test scores. If your teachers genuinely believe you can reach a higher level, they’re allowed — and often encouraged — to predict a slightly better grade.

What you should do:

• Have an open conversation with your IB coordinator early on about how predicted grades are set.
• Make sure your teachers understand your progress and potential — it’s totally normal for strong applicants to receive optimistic (but reasonable) predictions.

Just remember: these grades shouldn’t be pulled out of thin air. They should reflect your upward trajectory and what you’re capable of delivering on exam day.

The Admissions Tests

Oxford and Cambridge both require additional entrance exams, depending on your subject. These tests are less about memorized knowledge and more about how you think — your logic, reasoning, and analytical skills.

Here are a few examples:

• TSA (Thinking Skills Assessment) — for Economics or PPE at Oxford
• LNAT — for Law at Oxford
• BMAT — for Medicine at Oxford and Cambridge
• MAT — for Mathematics and Computer Science at Oxford
• NSAA — for Natural Sciences at Cambridge

These exams can be tough — often very different from school-style questions — so be sure to start preparing well in advance. Practice papers are your best friend here.

The Oxbridge Interview

The interview isn’t just a conversation — it’s more like a focused academic discussion with university professors. They’re not testing how many facts you’ve memorized, but rather:

• How you think under pressure.
• How deeply you understand your subject.
• How flexible and logical your reasoning is.

Each interview usually lasts 20 to 30 minutes. Depending on your course, you might be asked to analyze a problem, respond to a text, or talk through a hypothetical situation. And yes — they will throw in unexpected questions to see how you handle the unknown.

Some real examples:

• “Can a society exist without a state?” (PPE, Oxford)
• “Why is snow white?” (Natural Sciences, Cambridge)
• “What role does chance play in history?” (History, Oxford)

Tips for nailing the interview: 

• Practice thinking aloud. Professors want to hear your reasoning, not just your conclusions.
• Do mock interviews with teachers, tutors, or even friends — the more practice, the better.
• Don’t be afraid to say “I’m not sure.” What matters is how you explore an unfamiliar idea, not that you know everything off the top of your head.

6. Frequently Asked Questions (FAQ)

— Do I need to take 4 HL subjects?

No — three Higher Level subjects are perfectly fine for Oxford and Cambridge. Both universities clearly state that they do not require four HLs.

That said:

1. If you're academically strong and applying for a highly competitive course (like Maths, Physics, Economics, or Law), a fourth HL can show ambition.
2. Just be careful: don’t sacrifice quality or burnout yourself just to squeeze in another HL. If it comes at the cost of your EE, TOK, or CAS — it’s not worth it.

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

This can happen — especially with subjects like Philosophy, Computer Science, or some HL Maths options.

You still have options:

1. Self-study + external exam: You can prepare on your own (or with a tutor) and sit the exam at another IB school or an official exam center.
2. Online IB courses: Some accredited online IB providers allow you to study specific subjects remotely and include them officially in your diploma.

The key is to check that the solution is recognized by the IB and properly coordinated with your school.

— Do TOK and EE scores actually matter?

Yes — and more than you might think. While they’re part of the “core,” they:

• add up to 3 bonus points to your total diploma score;
• demonstrate research and critical thinking skills, which Oxbridge loves;
• often come up in interviews — especially if your EE topic relates to the course you’re applying for.

In fact, a strong EE or TOK essay can sometimes compensate for a slightly lower subject grade, especially if your reasoning is deep and well-articulated.

— How important are extracurricular activities?

Oxbridge doesn’t want a laundry list of clubs and medals. Their top priority is academic curiosity and intellectual depth. That said, extracurriculars do matter — if they make sense.

They’re especially valuable when:

• They relate to your subject (e.g., Physics Olympiad, Philosophy course, or a research internship);
• They show initiative and leadership (e.g., founding a debate club, running a volunteer project, or launching a meaningful CAS initiative);
• They help tell your story — showing motivation, maturity, and independence.



The best activities are those that fit naturally into your Personal Statement and reflect genuine engagement, not just padding.

Final Thoughts

Getting your IB diploma and securing a place at a top UK university is no small feat — but it’s absolutely possible. The key is to understand the expectations early, build a smart strategy, and follow it consistently.

Want to explore more UK admissions paths? Check out these next steps:

Understanding A-Levels: Your Pathway to a UK University

A-level or IB: Which One to Choose? Comparing Two Pathways to UK Universities