In the IB Diploma, choose your subjects backwards: decide the kind of degree you may apply for, find out which subjects and levels those courses require, and only then fill the six slots. A student with an excellent total can still be turned down by a university because one required subject was missing or was taken at Standard Level. This is the most common avoidable mistake we see among IB students, and it is made at 15 or 16, two years before the application.
How the Diploma is built
- Six subjects, normally one from each group: language and literature, language acquisition, individuals and societies, sciences, mathematics and the arts.
- Three subjects at Higher Level (HL) and three at Standard Level (SL). A few students take four at HL.
- The arts slot can be used for a second subject from another group instead, which is how a student takes two sciences or two humanities.
- Mathematics comes as two courses, Analysis and Approaches (AA) and Applications and Interpretation (AI), each offered at SL and HL.
- The core: Theory of Knowledge, the Extended Essay, and Creativity, Activity, Service.
Why the choice matters more in the IB
A CBSE or ISC student who takes Science with Mathematics keeps most courses open by default. An IB student has only six slots and has to choose a level for each one. Universities, especially in the UK, Europe, Singapore and Hong Kong, state their requirements in exactly those terms: this subject, at this level, with this score.
The result is that two students with the same total are not equal. One has the subjects the course needs. The other does not, and no score in the other subjects makes up for it.
What different degrees usually ask for
- Engineering and physical sciences: Mathematics at HL, usually Analysis and Approaches, and Physics at HL. Chemistry is needed for chemical engineering and often welcomed elsewhere.
- Computer science: Mathematics at HL. Selective universities often specify Analysis and Approaches.
- Medicine: Chemistry, usually at HL, with Biology. Requirements differ from country to country more than for any other course.
- Economics: Mathematics, and at the most selective universities Mathematics AA at HL. Taking Economics itself is rarely compulsory.
- Psychology, law, business and the humanities: usually no fixed subject, but an essay-based subject at HL helps, and some business and psychology courses want Mathematics.
- Design and architecture: a portfolio matters as much as the subjects. Some architecture courses ask for Mathematics or Physics.
These are patterns, not rules. Every university publishes its own requirements, and they change. Check the course page of each university before the subjects are fixed.
Four mistakes that cost students a place
- Choosing Mathematics AI because it looks easier. For engineering, computer science, economics and the physical sciences, many universities ask for AA, and some will not accept AI at all.
- Dropping a science too early. A student who is unsure between engineering and medicine needs Physics, Chemistry and Biology kept open for as long as the school allows.
- Planning only for one country. Subjects that satisfy a university in the USA may not satisfy one in the UK or in India. If India is a possibility, check what Indian universities and entrance exams require of IB students. Medicine in India needs Physics, Chemistry and Biology together, which the usual Diploma structure does not easily allow, so speak to the IB coordinator early.
- Choosing levels by what friends are taking. HL subjects should be the ones the degree requires and the student is strongest in. Everything else can be SL.
When to decide
Schools ask for IB subject choices during Class 10. That means the direction, at least the broad field, has to be clear before then. It is the reason we advise IB students to begin career counselling in Class 9, and it applies in the same way to IGCSE and ICSE students, who choose their subjects a year or two earlier still.
A student does not need to have chosen a career at 15. They need to know which two or three fields are real possibilities, so that the subjects keep all of them open.
How we help IB students
At Global Careers the process starts with the Career Fit assessment, checked with the student in person, and a counselling session with the family. We then map the fields the student may enter to the subjects and levels that universities ask for, in each country the family is considering, and review the plan before the school’s deadline. See stream and subject selection in Grades 9 and 10 and school and board selection.
Call +91 99250 33239 or +91 95105 33239, or send us a message. Our office is at S-8, 3rd Floor, Central Plaza, opposite St. Thomas School, New Citylight, Surat 395007.