What are the hardest HSC subjects?

By UAC's 2025 scaling data, the mainstream courses with the strongest competition are English Advanced, Chemistry, Mathematics Advanced, Economics and Physics — their cohorts are the strongest in the state, so a high scaled mark is hardest to reach. Extension courses scale even higher because only the strongest students take them.

Are the hardest HSC subjects the same as the best-scaling ones?

Largely yes — and that's the point. A subject scales up precisely because its cohort is strong, which is also what makes it hard to place near the top. So the 'hardest' subjects are usually the ones that reward a strong result the most.

Does scaling tell me how hard a subject is to learn?

No. Scaling data measures how strong a subject's cohort is, not how difficult its content is. A subject can feel hard to study but scale down if its overall cohort is weaker, and vice versa. Use this page for competition strength, and talk to your teachers about content difficulty.

Should I avoid the hardest HSC subjects?

Not for that reason alone. Strong-cohort subjects scale up on average, so doing well in one tends to be worth more, not less. The evidence-based advice is to pick subjects you're genuinely good at and will work hard in — a strong result in a 'hard' subject beats a weak result in an 'easy' one.

Hardest HSC Subjects 2026 (NSW)

Data source: UAC scaling report, Table A3 (2025 HSC) · 2025 data · checked July 2026How we verify →

When students say "hardest", they usually mean "strongest competition" — and that is exactly what scaling data measures. By UAC's 2025 scaling, the toughest mainstream cohorts in NSW are English Advanced, Chemistry, Mathematics Advanced, Economics and Physics. Below is the ranking, straight from the data — with the honest caveat most guides skip.

Important: scaling data shows how strong a subject's cohort is, not how hard its content is to learn. A subject scales up because strong students take it — which is also what makes a top mark hard to reach. These are cohort-level averages, and each HSC mark scales across a range rather than by a fixed amount — but the tendency is clear: it does not mean you should avoid a strong subject, because a strong result in one tends to be worth more, not less.

The hardest mainstream HSC subjects by cohort strength

Ranked by average scaled mark per unit (out of 50) in UAC's 2025 report — the higher the scaled mean, the stronger the cohort. This is the list of subjects most students actually weigh against each other.

#	Course	Avg scaled mark /50
1	English Advanced	32.8
2	Chemistry	32.0
3	Mathematics Advanced	31.9
4	Economics	31.4
5	Physics	31.0
6	Studies of Religion I	27.7
7	Studies of Religion II	27.3
8	Software Engineering	26.7
9	Biology	26.2
10	Engineering Studies	26.2
11	Legal Studies	25.3
12	Geography	25.2

A few small, self-selected cohorts (Music 2 and background-speaker language courses) scale higher still. See the full ranked list on our best- and worst-scaling HSC subjects page, or how scaling works on the HSC scaling page.

Extension courses scale highest of all

The very top of the scaling list is held by extension courses — Mathematics Extension 2, Latin Extension, Mathematics Extension 1, Italian Extension — because only the strongest students take them on top ofthe 2-unit course. They aren't a "hardest subject" choice so much as an add-on for students already excelling.

And the lowest-competition HSC subjects

The mainstream courses with the weakest cohorts by the same 2025 data. "Easier competition" is a double-edged sword: these subjects scale down on average, so a strong mark there tends to count for less towards your ATAR.

So which HSC subjects should you actually pick?

The data can rank competition, but it can't choose for you. The evidence is consistent: your mark in a subject depends far more on your effort and fit than on its scaling. Pick subjects you're genuinely good at and will work hard in — then let scaling reward the result. If you're weighing which of several strong subjects to take, see whether they scale up or down, plan a full line-up on our HSC subject combinations page, and check each subject's full scaling profile. When you have predicted marks, see how they feed your rank in how the HSC ATAR works.