IB or A-levels: what the choice changes for UK and US applications
IB or A-levels: what the choice changes for UK and US applications
Families choosing a sixth form are usually choosing a curriculum at the same time, without always seeing how differently the two are read at the other end. What changes in a UCAS application, in a US application, and in the two years in between.
Two different shapes
A-levels ask for depth in three subjects and let everything else go. The IB Diploma asks for six, three at Higher Level and three at Standard Level. They are drawn from language and literature, a second language, individuals and societies, the sciences and mathematics, with a sixth from the arts or a second subject from one of those groups. Alongside all six runs the core: Theory of Knowledge, assessed by a 1,600-word essay and an exhibition, the Extended Essay of 4,000 words, and creativity, activity and service.
From that structure, the arithmetic follows. Each subject is graded from 1 to 7, which gives 42 points, and the Extended Essay and Theory of Knowledge contribute up to three more, for a maximum of 45. At the bottom end, the diploma is awarded from 24 points. Creativity, activity and service carries no points at all, although a student who does not complete it receives no diploma whatever the examination results say.
How UK offers are written
Of course, both qualifications go through the same UCAS form and are read against the same criteria. The difference lies in how an offer is worded rather than in how seriously it is taken. Oxford asks for 38, 39 or 40 points including core points, depending on the course, with 6s and 7s at Higher Level. Cambridge sets its minimum at 41 or 42 points with 776 at Higher Level. Churchill, Corpus Christi and Selwyn usually ask above that, and some colleges want 777 or a higher total again.
One line in the Cambridge guidance decides subject choices rather than grades, and it is the one families miss: Higher Level subjects meet its A-level subject requirements, while Standard Level subjects meet its AS-level requirements. A student who takes a required subject at Standard Level has therefore not met a requirement written for A-level, however high the overall total. As such, the three Higher Level subjects have to be chosen against the courses under consideration. That choice is made at 16, well before most students have a settled list.
Mathematics is where this goes wrong most often
The IB runs two mathematics courses, Analysis and Approaches and Applications and Interpretation, and universities do not treat them as interchangeable. For any course that requires mathematics at all, Cambridge expects Higher Level Analysis and Approaches. Oxford accepts either course at Higher Level, with the exception of Chemistry. Any student weighing engineering, economics, mathematics or the physical sciences would be taking Analysis and Approaches at Higher Level, and in practice that is settled in the first term.
What US colleges make of each
American applications run on a different timetable, which changes what a qualification contributes. Since decisions arrive months before either set of final results, colleges work from GCSEs, any AS results, predicted grades and the school's own report. Both curricula are well understood by admissions offices that see British applicants regularly, and neither carries an advantage of its own.
That being said, the diploma fits the shape of an American transcript more comfortably. A US application assumes breadth across English, mathematics, a science, a social science and a language, which is more or less the diploma's structure. A student who dropped mathematics and every language at 16 has a gap to account for instead. A-levels are read as advanced work, much as Advanced Placement courses are, so three strong ones in the right subjects answer the depth question and leave breadth to the GCSE record.
The Extended Essay is worth more than its points
For applications in either direction, the Extended Essay is the most useful thing the diploma produces. It is a 4,000-word piece of independent research, supported by around 40 hours of work and three reflection sessions with a supervisor, the last of which is the viva voce. For essays assessed from May 2027 it is marked out of 30 across five criteria, and discussion and evaluation carries eight of those marks, more than any other criterion.
In an application, its value is separate from its grade. The second UCAS question asks how your studies have prepared you. A student who set a research question, found the evidence would not support their first answer, and rebuilt the essay around a narrower claim is describing undergraduate work from the inside. A-level students reach the same place through an EPQ, and those who are offered one and turn it down give up the best material they would have had for that question.
Which one suits which student
In our experience, the school matters more than the system. A school that has taught the diploma for 20 years, with a settled group of Higher Level teachers, will serve a student better than one that adopted it two years ago. The same holds in reverse for A-levels, where a strong department is worth more than the badge on the prospectus. Beyond that, the choice turns on how decided the student already is. Someone who knows the subject they want, and finds the rest a distraction, will do more with three A-levels and the hours a fourth subject would have taken. Someone still undecided, or keeping mathematics and a language alive for a possible US application, is better served by six subjects and the core.
As for workload, it is the other consideration, and it is misread in both directions. The diploma spreads its pressure across two years through internal assessments, the Extended Essay and Theory of Knowledge, so relatively little of it lands at once. A-levels concentrate almost everything into a single examination series at the end. That suits students who work well under that kind of pressure, and it is unforgiving of those who do not.
What to check before enrolment
Provided the subject requirements are met, neither route closes a door the other keeps open, and those requirements are worth checking now rather than in Year 13. Take the courses a student might plausibly apply for, find the entry requirements on each department's own pages, and read them for named subjects at Higher Level or A-level rather than for the headline grades. Ten minutes of that would tell a family more than any comparison of the two systems in the abstract.
Our note on choosing A-levels with the grades in front of you covers the combinations that narrow a list, and reading the syllabus before you apply explains where those requirements are published. Applicants aiming at Oxford or Cambridge will find the timetable on our Oxbridge admissions page, and families applying in both directions should read our US college admissions page alongside it. If you would like to talk a curriculum choice through before a school's deadline, that is the kind of decision our school and exam support was set up to help with.
