HSC assessment, explained

HSC ATAR calculator

Enter the HSC marks you expect (or already have) and get a rough ATAR. It runs NESA/UAC's published best-10-units rule over UAC's own 2025 scaling report for the HSC — the same relativities UAC uses, read at the precision UAC actually publishes.

Scaled marks and the aggregate-to-ATAR table are from UAC's own 2025 HSC Scaling Report (uac.edu.au, published June 2026). This calculator applies NSESA/UAC's published best-10-units aggregate rule to those numbers. UAC's own report warns its percentile table is not a strict HSC-mark-to-scaled-mark function — a given HSC mark can scale to a range of marks depending on the rest of your course pattern — so this is a rougher estimate than the VCE calculator's, not an official ATAR, and does not include bonus points or special consideration.

Your subjects

At least 2 units of English — English Advanced, Standard, Studies or EAL/D each satisfy that on their own. Your aggregate is the best 10 units of ATAR courses, so a full 2-unit course counts twice as much as a 1-unit Extension — except Mathematics Extension 1 taken alongside Extension 2, which UAC counts as 2 units too (that's the "4-unit maths" pattern). Enter your HSC mark on that course's own scale: out of 100 for a 2-unit course, out of 50 for a 1-unit Extension. Leave a row blank if you're doing fewer than six courses.

/100

Only courses UAC published 2025 percentile data for are listed — a course under 40 students gets no percentile columns, same reason VTAC's report skips small studies. A few names are the nearest match rather than exact: "Mathematics Standard" uses Standard 2's numbers (Standard 1 isn't ATAR-scored), "Health and Movement Science" uses the outgoing PDH&PE course's 2025 data, and each language is its mainstream Continuers course.

Subject	Raw	Scaled
English Advanced *	70	24.9
Mathematics Advanced	70	25.2
Biology	70	21.9
Chemistry	70	27.8

You've entered 8 units — the best-10-units rule needs 10 for a full aggregate. Add 2 more.

Scaled aggregate (best 10 units) 199.46

57.07

estimated ATAR, roughly 54–60

* a course in the English group. UAC's own report warns its percentile table "should not be used as a simple HSC to scaled mark conversion table" — a given HSC mark can scale to a range of marks depending on the rest of your course pattern — so this estimate carries a wider band than the VCE calculator's, on top of not knowing your real moderated marks or any bonus points.

How an HSC ATAR is actually built

The best-10-units rule

Your aggregate is the best 10 units of ATAR courses you completed, including at least 2 units of English, each scaled mark counted on a 1-unit basis (so a full 2-unit course counts double a 1-unit Extension) and capped at 500 overall. Fewer than 10 units, or less than 2 of them English, and UAC won't calculate an ATAR.

Scaling

Your HSC mark in one course is not what goes into that sum. UAC scales every course against how the students who took it performed across their other ATAR courses, the same principle VTAC uses in Victoria — a mark in a course that mostly attracts strong all-round students scales differently to the same mark in one that doesn't. UAC is explicit that this isn't a pure function of one course's mark alone: your scaled mark also depends on what else you studied.

How your HSC mark is set

The HSC mark itself already blends your school-based assessment with your exam result — NESA moderates the school assessment against your cohort's exam performance before that mark is finalised, so the number this calculator takes as input has already been through that process once. How HSC assessment is actually marked is its own guide.

Practise the subjects that move it most

The courses with the lowest scaled marks above are the ones where a few extra marks change your aggregate the most. StudyDesign AI marks a written answer against the real NESA criteria for your course and shows exactly which criterion was missed, so you can see where those marks actually are.

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