How to Choose the Right HL and SL Subjects?

Choosing the right subjects in the IB Diploma Programme isn’t just about ticking boxes. It’s a major decision that can impact your motivation, performance, and even university options. With the distinction between IB HL and SL levels, plus the broad array of subject offerings, how can you make smart, confident choices?

In this guide, we’ll walk you through how to approach your IB subject selection in a way that plays to your strengths, supports your goals, and keeps your stress in check.

What’s the Difference Between HL and SL?

When starting your IB subject selection, one key decision involves whether to take each subject at Higher Level (HL) or Standard Level (SL). These two levels differ significantly in content depth, time commitment, and assessment style, and your choices here can shape both your workload and your university readiness.

Below is a breakdown to help you understand how they compare and how to choose the right mix.

Feature	HL (Higher Level)	SL (Standard Level)
Teaching Hours	~240 hours	~150 hours
Content Depth	Advanced theory, extended material	Core curriculum, foundational content
Assessment Load	Extra papers or internal components	Fewer and/or shorter assessments
Best For	Subject strengths, uni prerequisites	Broad exposure, manageable balance
Example	HL Chemistry: in-depth lab analysis	SL Chemistry: core theory without extensions

What Is HL?

HL subjects go deeper into the subject matter and are designed for students who either enjoy the topic intensely or need it for university prerequisites. They also tend to be more demanding, both in terms of classroom hours and assessment requirements.

• Roughly 240 teaching hours across two years

• Covers advanced content, sometimes including entire units not seen at SL (e.g., calculus in HL Math)

• Involves additional exam papers or more rigorous internal assessments

• Recommended for students aiming for university programs that list HLs as prerequisites

If you’re strong in the subject or plan to pursue it at the tertiary level, HL is worth considering.

What Is SL?

SL subjects cover the core components of the subject but skip many of the more challenging or extended parts included in HL. They're ideal for students who want exposure to the subject without the full HL intensity.

• Roughly 150 teaching hours across two years

• Focuses on foundational skills and key ideas

• Typically involves fewer assessments or shorter exam papers

• Helps maintain a manageable workload, especially when paired with three or four HLs

SL subjects still carry full academic weight. They’re part of your final score and require a strong performance to succeed.

Factors to Consider in Your IB Subject Selection

While some students focus on IB subject selection that simply looks good on paper, the smarter approach is to choose a subject mix you can genuinely thrive in. Here are factors to help guide that decision.

1. Personal Interest and Academic Strengths

Choose IB subjects that genuinely interest you. If you love writing and analysis, HL English might be perfect. If you’re more numbers-focused, HL Math could be the challenge you need. Picking subjects aligned with your strengths increases your chances of enjoying the process and doing well.

2. Future University and Career Requirements

Some university courses require specific subjects at HL. For example, Engineering might require HL Math and Physics, while Medicine may ask for HL Biology and Chemistry. Research your dream universities and use that to guide your subject selection.

3. Overall Subject Balance and Workload

While students must take at least three HLs, taking four might not be necessary — or wise — if it stretches you too thin. A well-balanced IB HL and SL combination will let you challenge yourself without burning out.

4. Availability of Resources and Support

Before selecting a subject, consider what kind of resources your school offers for it. Even if you're passionate about a topic, limited support can make it unnecessarily difficult.

5. Performance in Related or Prerequisite Subjects

Think about your past academic performance. If you struggled with IGCSE Biology, HL Bio might be a stretch. Use your earlier results as a guide when narrowing down your IB subject selection.

Common IB Subject Selection Mistakes to Avoid

Making the right subject selection is just as much about avoiding the wrong influences. Below are common mistakes students make:

Letting Peer Pressure Dictate Choices

Just because your friends are taking HL Econ doesn't mean it's right for you. Choose based on fit, not FOMO. Consider how the subject aligns with your skills, interests, and long-term academic goals.

Underestimating SL Subjects

A common trap is thinking SL subjects are “easy.” Many SLs still require rigorous assessment and are factored into your final grade, especially in subjects like SL Maths or SL Literature, which demand a strong foundational understanding.

Picking HLs Just to Impress

Don’t take HL Chemistry just to seem competitive. If you’re not prepared, the stress will show in your results. HLs come with heavier workloads, complex assessments, and deeper theoretical expectations that shouldn’t be taken lightly.

Overlooking University Prerequisites

Some students pick what they love but forget what they need. Always check that the subjects you’ve enrolled in are aligned with your future academic plans, particularly for programs that require specific HL combinations like Engineering or Medicine.

Not Seeking Advice or Researching

You’re not expected to know everything on your own. Speak to teachers, advisors, and check out official IB subject resources or university program websites before locking in your choices and committing to a study path.

Set Yourself Up for IB Success

More than an academic formality, your IB subject selection is a strategic decision that can shape your entire IB experience and beyond. It’s a chance to explore your interests, play to your strengths, and challenge yourself wisely.

If you're still unsure about your subject selection, HKExcel is here to help. With expert tutoring and personalized guidance, we can help you select the best IB HL and SL subjects to match your goals and support you through them every step of the way.