Every year after ATARs are released, one question dominates conversations among Year 12 students and parents:
“How did subjects scale?”
The HSC ATAR 2025 Scaling Report helps answer exactly that. It explains how raw HSC marks were adjusted by UAC to calculate ATARs — and why two students with the same HSC mark can end up with very different outcomes.
KIS Summary:
- What scaling actually is
- Which subjects scaled up and down in 2025
- Misconceptions about scaling
- What students should take away from the report
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What is HSC scaling (and why does it exist)?
HSC scaling is the process used by UAC to adjust students’ marks so that ATARs reflect overall academic achievement, not just raw exam scores.
Importantly, scaling is not about how “hard” a subject is. It’s about the academic strength of the cohort taking that subject.
In simple terms:
- Subjects taken by high-performing cohorts tend to scale up
- Subjects taken by mixed-ability cohorts tend to scale down
This ensures students aren’t advantaged or disadvantaged simply because of their subject choices.
Key takeaways from the 2025 Scaling Report
1. High-maths subjects continue to scale strongly
As in previous years, advanced maths subjects were among the strongest scaling subjects in 2025.
- Mathematics Extension 2
- Mathematics Extension 1
- Mathematics Advanced
These subjects are typically taken by students who perform well across all their subjects, which pushes scaling upward.
Takeaway: These subjects reward strong performance — but they’re not “easy marks”. Weak results in high-scaling subjects can still hurt your ATAR.
2. Sciences remain solid but competitive
Subjects like:
- Physics
- Chemistry
- Economics
continued to scale moderately well, reflecting strong but broad cohorts.
However, scaling gains were smaller than many students expect, especially for average marks.
Takeaway: Science subjects scale best when paired with strong overall academic performance.
3. English subjects scale closer together than students think
In 2025, scaling differences between:
- English Advanced
- English Standard
- English Extension
were much smaller than common myths suggest, especially around the middle of the cohort.
At the top end, Extension subjects still benefit strong students — but English alone rarely “makes or breaks” an ATAR.
Takeaway: Your rank in English matters far more than the label of the course.
4. HSIE and creative subjects still scale down — but context matters
Subjects such as:
- PDHPE
- Society & Culture
- Visual Arts
- Drama
generally scaled down in 2025, consistent with historical trends.
However, top students in these subjects still achieved strong ATARs, especially when combined with higher-scaling subjects.
Takeaway: Scaling down doesn’t mean a subject is “bad” — it just means performance needs to be strong to compensate.
Subject-by-Subject Scaling Summary (HSC 2025)
Important: Scaling depends on the cohort, not the subject itself. The table below shows typical scaling behaviour, not guaranteed outcomes.
| Subject | Typical Scaling Outcome | What This Means in Practice |
|---|---|---|
| Mathematics Extension 2 | Scales very high | Rewards top students strongly; weak marks are punished |
| Mathematics Extension 1 | Scales high | Strong benefit for students with high overall academic performance |
| Mathematics Advanced | Scales moderately high | Solid scaling, especially for above-average students |
| Mathematics Standard | Scales down | High marks still help, but scaling limits ATAR upside |
| English Extension 2 | Scales high | Small cohort; strong benefit for top students |
| English Extension 1 | Scales moderately high | Helps strong writers but doesn’t guarantee gains |
| English Advanced | Scales slightly down / neutral | Rank matters far more than course label |
| English Standard | Scales down | Strong ranks still contribute meaningfully |
| Physics | Scales moderately | Best results when combined with strong maths |
| Chemistry | Scales moderately | Competitive cohort; solid scaling for high achievers |
| Biology | Scales slightly down | Performance matters more than subject choice |
| Economics | Scales moderately | High-performing cohort drives scaling |
| Business Studies | Scales down | Strong ranks still beneficial |
| Legal Studies | Scales down | Band 6 outcomes still valuable |
| Modern History | Scales down | Writing quality and rank are key |
| Ancient History | Scales down | Scaling similar to Modern History |
| PDHPE | Scales down | Popular subject with broad cohort |
| Society & Culture | Scales down | Excellent results still possible with strong performance |
| Visual Arts | Scales down | Marking consistency and rank are critical |
| Drama | Scales down | Top students can still achieve strong ATARs |
| Music 1 | Scales down | Performance varies by cohort strength |
| Music 2 | Scales moderately | Smaller, stronger cohort than Music 1 |
| Languages Extension | Scales high | Very strong scaling for top students |
| Languages Continuers | Scales moderately | Depends heavily on candidature strength |
| Studies of Religion II | Scales slightly down | Strong ranks still contribute well |
The biggest scaling myth (that won’t go away)
“You should choose subjects that scale well.”
This is the most common mistake students make.
UAC has repeatedly shown that:
- Students perform best in subjects they are good at
- Strong performance in a lower-scaling subject beats weak performance in a higher-scaling one
A Band 6 in a lower-scaling subject almost always helps more than a mediocre result in a “high-scaling” subject.
What actually determines your ATAR
Your ATAR is driven by:
- Your rank within each subject
- The academic strength of the cohort
- Your performance across all subjects combined
Scaling simply aligns these factors — it doesn’t override them.
How students should use the 2025 Scaling Report
The scaling report is best used to:
- Understand why your ATAR looks the way it does
- Compare outcomes across subjects realistically
- Make informed (not fear-based) subject choices for Year 11
It should not be used to:
- Panic about “bad” subject choices
- Assume certain subjects guarantee high ATARs
- Undervalue subjects you genuinely enjoy and perform well in

Final advice for future HSC students
If there’s one lesson from the HSC ATAR 2025 Scaling Report, it’s this:
Your performance matters more than your subjects.
Students who:
- Choose subjects aligned with their strengths
- Focus on ranks, not raw marks
- Study consistently and strategically
will outperform students chasing scaling alone — every single year.
If you want an estimate of what your ATAR might be, you can use an ATAR Calculator:

For more study tips and resources, check out these KIS Academics resources:
FAQs
How is the ATAR Calculated?
ATAR is calculated differently in different states, and each state also has its own requirements. Find out more in these articles:
What is the purpose of scaling in the HSC
Scaling balances differences in difficulty and student ability across subjects to ensure fair ATAR calculations.
Do harder subjects always scale up?
- Not always. Subjects like Extension Maths and Physics sometimes scale up because students sitting them tend to do well across all their subjects— not because the course itself is “harder”.
- Scaling is based on cohort performance, not perceived difficulty. If students in a subject do well in their other subjects, that subject tends to scale up.
