When your child enters the IB Diploma Programme, one of the first major decisions they face is which subjects to take at Higher Level (HL) and which to take at Standard Level (SL). For many families navigating this for the first time, the distinction can feel unclear and the stakes feel high. Which HL courses will universities actually require? Is it worth taking four HL subjects? What happens if your child chooses the wrong level going into Grade 11?
This guide breaks down what IB HL and SL actually mean, how universities interpret these choices, and how to make strategic decisions that align with your child’s academic strengths and university goals.
What Is the Difference Between IB HL and SL?
IB Higher Level (HL) and Standard Level (SL) courses cover the same six subject groups but differ significantly in depth and workload. HL courses require approximately 240 teaching hours over two years, compared to 150 hours for SL courses. The content goes deeper, assessments are more demanding, and the internal assessment components differ as well.
Here is a quick comparison of IB HL vs SL:
| Feature | Higher Level (HL) | Standard Level (SL) |
|---|---|---|
| Teaching hours | ~240 over 2 years | ~150 over 2 years |
| Score range | 1 to 7 | 1 to 7 |
| Depth of content | Extended, more complex | Core curriculum only |
| University weighting | Often specified in requirements | Counts toward overall score |
| Typical weekly workload | Significantly heavier | Moderate |
Every IB Diploma student must take exactly three HL subjects and three SL subjects, for a total of six. Some students take four HL subjects, which we address below.
How Many HL Subjects Does Your Child Need for Competitive University Admissions?
Three HL subjects is the IB minimum, and for most university programs, three well-chosen HL courses are sufficient. Competitive programs do not typically require four HL subjects, but they do specify minimum scores in particular HL subjects. This is the detail most families miss when planning the IB course load.
Here are some common university HL expectations based on our work with students applying to top programs:
- Engineering at Waterloo: Typically requires HL Mathematics (AA or AI) with a score of 5 or higher, often accompanied by HL Physics or HL Chemistry depending on the engineering discipline.
- Life Sciences at McGill, U of T, or UBC: Usually requires HL Chemistry and HL Biology, with minimum scores around 5 to 6 for the most competitive programs.
- Commerce at Ivey or Schulich: HL Mathematics is strongly preferred and often specified, particularly for students applying from IB schools.
- Oxbridge (Oxford and Cambridge): Frequently expect a 7 or near-7 in the HL subject most relevant to the intended course. Their offers are often score-specific and binding.
- Ivy League and selective US liberal arts: No uniform HL requirements, but a strong HL profile in relevant subjects significantly strengthens the application.
Always verify requirements directly with the university’s admissions page, as IB entry requirements can shift year to year.
Which Subjects Should Your Child Take at HL vs SL?
The right HL subjects depend on three factors: your child’s intended university program, their natural academic strengths, and the university-specific HL requirements they need to meet. A strategically chosen HL profile directly increases the chances of meeting conditional offer requirements at top schools.
A practical framework for IB HL vs SL selection:
- Identify the target university programs first. Look up each school’s published IB requirements. Waterloo Engineering, U of T, and McGill all publish specific IB subject requirements online.
- Select HL in subjects that are required or strongly preferred for those programs. These choices are non-negotiable if the program is the goal.
- Use the remaining HL slot strategically. A student aiming for business might take HL History or HL English alongside HL Math, which demonstrates intellectual breadth and can strengthen a liberal arts or business application.
- Use SL for required subjects where the HL version offers diminishing returns. A student pursuing commerce does not need HL Chemistry. Taking it at SL satisfies group requirements without adding unnecessary workload.
Based on our work with IB students at schools including Upper Canada College, Havergal College, Branksome Hall, and Crescent School, the most common mistake families make is choosing HL subjects based on what sounds impressive rather than what aligns with both the student’s strengths and the actual requirements of their target programs. An HL course that results in a 4 or 5 when the program expects a 6 is far more damaging than a well-chosen SL course at the same school.
You can learn more about the subjects and levels our tutors support on our areas of practice page.
Is It Worth Taking Four HL Subjects?
Four HL subjects is not recommended for most students. Students who take four HL subjects without sufficient academic support routinely find that their overall diploma score suffers, which can hurt admissions outcomes more than the extra HL helps.
The students who genuinely benefit from a four-HL load are typically those who:
- Are applying to programs with conflicting HL requirements, such as a student keeping both medicine and engineering options open
- Have demonstrated exceptional ability in Grade 10 across all four subject areas, with strong teacher endorsements
- Have access to consistent academic support throughout both years of the diploma
A student who earns 38 points on three well-chosen HL subjects will generally be more competitive than a student who earns 34 points across four HL subjects. Experienced IB educators consistently emphasize depth over breadth when it comes to HL selection.
How Can You Support Your Child Through Their HL Coursework?
HL coursework is genuinely rigorous. According to experienced IB educators, HL Mathematics AA and HL Physics are among the most demanding courses in any high school curriculum worldwide. Students benefit most from support that begins early in Grade 11, before Internal Assessment deadlines and the accumulation of the workload make catching up difficult.
Practical steps parents can take:
- Establish a sustainable weekly study routine early in Grade 11, before Internal Assessment work begins in earnest.
- Arrange subject-specific support in HL subjects where the jump from Grade 10 is sharpest, particularly Mathematics, Sciences, and Economics.
- Monitor Internal Assessment deadlines, which typically fall in January of Grade 12 and carry 20 to 30 percent of the final subject score.
- Review predicted grades with your child’s teachers by the end of Grade 11, and take action early if predicted grades fall below target program minimums.
If you are planning your child’s IB course load or they are already in the diploma and finding one or more HL subjects challenging, reach out to Polaris Tutors to connect with an educator who has deep experience with the IB curriculum.
Frequently Asked Questions About IB HL and SL
How many HL subjects does a student need for the IB Diploma?
The IB requires a minimum of three HL subjects. Most students take exactly three. Taking four HL subjects is optional and should only be considered when specific university programs require subjects that would otherwise exceed three HL choices.
Do universities specify which subjects must be at HL?
Yes. Many competitive programs at Canadian, American, and UK universities specify required HL subjects and minimum scores, not just overall diploma totals. Engineering, medicine, and sciences programs commonly require HL Mathematics and at least one HL Science. Always check the admissions page of each target program directly.
Can my child switch from HL to SL after starting the IB Diploma?
Switches from HL to SL are possible but must happen within the first few months of Grade 11. Schools typically have a window in October or November for level changes. Switching after this period is generally not permitted and late switches can affect predicted grades and teacher relationships.
What is a competitive HL score for Canadian university admissions?
Most competitive programs at Waterloo, McGill, Queen’s, and U of T specify a minimum of 5 in required HL subjects. The most selective programs, including Waterloo Computer Science and McGill Medicine, often expect 6 or 7 in relevant HL courses. Oxbridge offers can specify a 7 in a named HL subject as a condition.
Should my child take HL in a subject they find easy or one that challenges them?
A mix of both is ideal. At least one or two HL choices should align directly with program requirements, regardless of difficulty. The remaining HL slot should go to a subject where your child is genuinely strong and likely to score a 6 or 7, as a high HL score in a challenging subject demonstrates real ability to admissions committees.
Final Thoughts
Choosing between IB HL and SL is one of the most consequential academic decisions a student makes before Grade 11. The right combination balances university requirements, genuine subject strength, and a realistic assessment of a two-year workload. For most students aiming at competitive programs, three carefully selected HL subjects outperform four HL subjects taken under strain, with lower scores across the board.
Polaris Tutors specializes in supporting IB students at private and independent schools across Canada, the United States, and internationally. If you want guidance on course selection or one-on-one support in any HL subject, contact us here to connect with an experienced IB educator.