What is the International Baccalaureate (IB)?

What is the International Baccalaureate?

The International Baccalaureate (IB) is a globally recognised educational programme designed for students aged 16 to 19. Founded in Geneva in 1968, it is now offered in more than 160 countries and is widely respected by universities around the world, including all UK Russell Group institutions.

When parents talk about "the IB" in the context of sixth form, they almost always mean the IB Diploma Programme - a two-year qualification that sits alongside A-Levels as one of the main routes to university in the UK.

The IB is underpinned by a philosophy of breadth and international-mindedness. Where A-Levels typically mean specialising in three or four subjects, the IB requires students to study six subjects simultaneously, spanning a wider range of disciplines. This makes it a demanding but rewarding route for the right student.

How the IB Diploma is Structured

The IB Diploma has two distinct parts: the six academic subjects and the core components. Both must be completed to earn the full Diploma.

The Six Subject Groups

Students choose one subject from each of six groups, ensuring breadth across the curriculum:

1. Studies in Language and Literature - usually the student's first language (English Literature in most UK schools)
2. Language Acquisition - a second language, studied at ab initio (beginner) or language B (intermediate/advanced) level
3. Individuals and Societies - includes History, Geography, Economics, Psychology, Business Management, and others
4. Sciences - Biology, Chemistry, Physics, Computer Science, Environmental Systems and Societies, Sports Exercise and Health Science
5. Mathematics - either Mathematics: Analysis and Approaches (more abstract, suited to maths-heavy university courses) or Mathematics: Applications and Interpretation (more applied)
6. The Arts - Visual Arts, Music, Theatre, Film, or Dance. Students who prefer not to take an arts subject can replace this group with an extra choice from groups 1–4

Higher Level and Standard Level

Each subject is studied at either Higher Level (HL) or Standard Level (SL). Students must take exactly three subjects at HL and three at SL. HL subjects involve more teaching hours (typically 240 hours over two years versus 150 hours for SL) and are assessed at greater depth.

University admissions offers are generally conditional on HL grades. A student applying to read Medicine, for example, would typically be expected to achieve 6 or 7 in HL Chemistry and HL Biology.

The IB Core

Alongside the six subjects, all IB Diploma students complete three compulsory core components. These are what most distinguish the IB from A-Levels and are central to its educational philosophy.

Theory of Knowledge (TOK)

TOK is a unique philosophy and epistemology course that asks students to think critically about how we know what we know. Students explore questions such as: how does scientific knowledge differ from historical knowledge? What role does language play in shaping understanding? TOK is assessed through an exhibition of objects linked to a prompt, and a 1,600-word essay on a prescribed title set by the IB. It contributes up to 3 bonus points to the total Diploma score.

The Extended Essay (EE)

The Extended Essay is an independent, self-directed piece of academic research of up to 4,000 words on a topic of the student's choosing, supervised by a school mentor. It is the closest thing in pre-university education to a university dissertation and is excellent preparation for undergraduate study. Like TOK, it contributes bonus points (up to 3, combined with TOK) to the final score.

Creativity, Activity, Service (CAS)

CAS requires students to engage in a programme of activities beyond the academic curriculum. Creativity might include art, music, or drama; Activity covers physical pursuits such as sport or dance; Service involves community engagement or charity work. CAS is not formally graded but must be completed satisfactorily - failure to do so means students cannot receive the Diploma, regardless of their academic results.

How IB Grading Works

Each of the six subjects is graded on a scale of 1 to 7, where 7 is the highest. The maximum score from the six subjects is therefore 42. The TOK essay and Extended Essay combined can award up to an additional 3 bonus points, bringing the maximum possible Diploma score to 45 points.

To be awarded the Diploma, students must achieve a minimum of 24 points overall, with no grade below 3 in any subject, and must have completed all CAS and core requirements. Most competitive UK universities ask for 38 or above; the very top courses (Medicine at Oxbridge, for example) may require 40–42.

IB to UCAS Tariff Conversion

UCAS assigns tariff points to IB scores to help universities compare them with A-Level grades. The conversion is approximate, but the following gives a useful guide:

• 45 points = 168 UCAS tariff points
• 40 points = 128 UCAS tariff points
• 38 points = 116 UCAS tariff points
• 35 points = 96 UCAS tariff points
• 32 points = 80 UCAS tariff points
• 30 points = 72 UCAS tariff points

The UCAS tariff is useful for comparing headline scores, but many competitive universities set subject-specific conditions (particularly on HL grades) rather than relying solely on total points.

IB vs A-Levels: A Practical Comparison

The choice between the IB and A-Levels is one of the most important decisions a student and family will make at the end of Year 11. Both are respected by UK universities, but they suit different learners.

Factor	IB Diploma	A-Levels
Number of subjects	6 (compulsory)	Typically 3
Compulsory components	TOK, Extended Essay, CAS	None beyond subjects
Breadth	High - arts, sciences, languages all required	Lower - deep specialism possible
Independent research	Yes (Extended Essay)	Only via EPQ (optional)
Workload	Very high	High but more focused
Assessment	Mix of exams and coursework/internal assessment	Predominantly linear exams at end of Year 13
University recognition (UK)	Excellent - all Russell Group universities accept it	The standard expectation
International portability	Very high	Variable - some countries do not recognise A-Levels

The IB suits students who are genuinely curious across multiple disciplines, who enjoy writing and independent research, and who may be considering studying or working abroad. A-Levels suit students who have a clear sense of direction and want to go deep in a focused set of subjects.

Which UK Schools Offer the IB?

The IB is offered by a relatively small number of UK schools compared to A-Levels. In England, roughly 200 schools and colleges are IB World Schools - a mix of independent schools, international schools, and a smaller number of state sixth-form colleges.

Well-known independent schools offering the IB include Sevenoaks School (which replaced A-Levels entirely with the IB in 1995), the United World Colleges, Hurtwood House, and a number of London day schools. Several state sixth-form colleges - including some in London and the South East - also offer the IB as an alternative to A-Levels.

If the IB is a priority for your family, it is worth filtering your school search explicitly, as availability is geographically uneven and competition for places at state IB schools can be high.

Search sixth forms and colleges on School Signal to find IB schools in your area.

Pros and Cons of the IB Diploma

Advantages

• Breadth of study - students leave with genuine competence across sciences, humanities, and languages, which many employers and universities value
• International recognition - particularly valuable if the student may study or work outside the UK
• University preparation - the Extended Essay and TOK closely mirror the demands of undergraduate study
• Holistic development - CAS ensures students remain rounded and engaged outside the classroom
• Internal assessment diversity - ongoing coursework and practicals reduce reliance on a single set of final exams

Disadvantages

• Very demanding workload - six subjects plus three core components is genuinely challenging and not suitable for all students
• Limited availability - far fewer schools offer the IB than A-Levels, which may restrict choices geographically
• Less flexibility - the compulsory breadth can frustrate students who know exactly what they want to study and want to specialise early
• Language requirement - studying a second language is compulsory, which some students find difficult
• Cost - IB schools are more commonly fee-paying; state IB provision is limited

Is the IB Right for Your Child?

The IB is not inherently better or worse than A-Levels - it is a different approach that suits a different type of learner. Students who thrive on the IB are typically those who enjoy all their subjects, are comfortable managing a large workload across multiple disciplines, and have a strong sense of self-motivation.

Students who have a clear passion for one or two subjects, or who find broad study overwhelming, will often be better served by A-Levels, which allow deeper specialisation.

The most important thing is to visit schools, speak to current students, and understand what the daily reality of each programme looks like - not just the headline comparisons.

Read our companion guide on what A-Levels are to compare the two routes in more detail.