An A Level class is viable when fee income from its students covers the teacher time and resources it needs. There is no official minimum. The only published benchmark, a 2017 study for England’s Department for Education, found schools judged the minimum viable size at 11.7 students on average. International schools should calculate their own break-even.
Is there an official minimum A Level class size?
No. Neither Cambridge nor Pearson sets one, and we found no international data. The nearest evidence is Decisions about A level class sizes, research by Isos Partnership for the DfE (DfE, March 2017):
| Finding (24 English providers, 2015-16) | Figure |
|---|---|
| Minimum viable class size, as judged by providers | 11.7 students on average |
| Average A Level class size, school sixth forms | ”Just under 11” |
| Average A Level class size, FE and sixth-form colleges | ”Just under 19” |
| Where costs exceeded £5,000 per student | ”Predominantly … institutions delivering average A level class sizes of fewer than 12” |
| Schools subsidising post-16 from pre-16 funding | ”Around half” believed they did |
It is a small, dated sample of state providers in England, funded per student by government. International schools are funded by fees, so the same logic applies but the numbers differ. The finding that school sixth forms typically run below their own viable size, cross-subsidised from younger years, is the pattern to check in your school.
How much teaching time does an A Level need?
Cambridge designs its syllabuses “based on learners having about 180 guided learning hours for each Cambridge International AS Level and about 360 guided learning hours for a Cambridge International A Level” (Cambridge 9709 syllabus). Cambridge adds that the hours needed “may vary according to each school”. Turned into a timetable:
| Course | Guided learning hours | Per year | Per week over 36 teaching weeks |
|---|---|---|---|
| Cambridge AS Level (one year) | About 180 | 180 | About 5 hours |
| Cambridge A Level (two years) | About 360 | 180 | About 5 hours |
The 36-week year is our assumption; use your school’s own. Five hours a week per subject, for each teaching group, is the staffing cost of every A Level offered, whether the class has 3 students or 15.
How do you calculate break-even class size?
Divide the cost of running the class by the fee income each student contributes to it:
Break-even students = (teacher cost for the class + subject resources) ÷ (fee income per student allocated to the subject)
Worked example with hypothetical round numbers, not data:
| Item | Hypothetical school |
|---|---|
| Teacher cost per teaching hour, fully loaded | 50 |
| Class hours per year | 180 |
| Teacher cost per class per year | 9,000 |
| Subject resources and exams administration | 1,000 |
| Total cost of the class | 10,000 |
| Sixth-form fee per student, after overheads | 3,000 |
| Share allocated to one of three A Levels | 1,000 |
| Break-even class size | 10 students |
Change any input and the answer moves. The value of the formula is that it makes the cross-subsidy visible, so leaders can decide it deliberately.
What are the options when a class is below break-even?
Five, in rough order of cost:
- Run it anyway, as a strategic subject, one the school considers central to its offer or its reputation. Decide this explicitly and cap how many subjects get it.
- Combine year groups. Teach Year 12 and 13 together where the syllabus structure allows, e.g. shared AS content.
- Reduce contact time carefully, with structured independent study. Keep in mind Cambridge’s 360-hour design.
- Partner or blend. Share a teacher with another school, or use a specialist online teacher. See delivering a subject without a specialist teacher.
- Withdraw it, with notice to families before options are chosen.
How should a school set its viability rule?
Write it into the options process, before students choose:
- Set a provisional minimum, such as the break-even number, and publish it with the options booklet.
- Decide exceptions in advance: which subjects are strategic, and for how long.
- Confirm viability at a fixed date, early enough for students to rechoose.
- Review the whole sixth form, not subject by subject. One small class may be affordable if others are full.
See adding A Levels: a planning guide for principals and Cambridge vs Edexcel IAL. Pearson’s modular IAL can change the arithmetic, since units can be timetabled across series.
How schools do this with AI Buddy
Small A Level classes are most at risk when the specialist teacher is stretched or shared. AI Buddy gives students past-paper-style Cambridge and Pearson Edexcel A Level practice with instant marking, including between lessons in blended or shared-teacher arrangements. Teachers get topic data to use limited contact time well. It supports teaching; it does not replace the teacher a viable class needs.
Frequently asked questions
How many students does an A Level class need to be viable?
There is no official minimum. Providers in a 2017 DfE study judged it to be 11.7 students on average. Schools should calculate their own break-even from teacher costs and fee income.
How many teaching hours does an A Level need?
Cambridge designs its A Levels for about 360 guided learning hours over two years, and AS Levels for about 180. That is roughly five hours a week per subject.
What is the average A Level class size?
In the DfE’s 2017 study of English providers, school sixth forms averaged just under 11 students per A Level class, and colleges just under 19.
What can a school do if an A Level class is too small?
Run it as a strategic subject, combine year groups, reduce contact time with structured independent study, partner or blend with another school, or withdraw the subject before options close.
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Sources
- Department for Education (Isos Partnership), Decisions about A level class sizes (March 2017)
- Cambridge International, AS & A Level Mathematics 9709 syllabus for 2026 and 2027, guided learning hours