How ATAR is calculated for Chemistry: QLD vs VIC vs NSW
The ATAR is the number that follows you into university applications, and it is the most misunderstood part of Year 12. The biggest misunderstanding is in the name: the ATAR is not a mark, it is a rank. It does not say "you scored 90 in Chemistry." It says "you finished ahead of this percentage of your age group, across all your subjects combined."
Every state arrives at that rank, but three different bodies calculate it three different ways. In Queensland it is QTAC, in Victoria it is VTAC, and in New South Wales it is UAC. This guide explains what the ATAR is, then walks through how each state turns your Chemistry result (and your other subjects) into one.
What the ATAR is, in every state
Before the differences, the shared definition. In all three states the ATAR:
- is a rank, not a mark. A UAC example: an ATAR of 80.00 means you are 20 per cent from the top of your age group, not your Year 12 group.
- runs from 0.00 to 99.95, in increments of 0.05, so the highest possible ATAR is 99.95.
- ranks you against your age cohort, not just the students who finished Year 12.
- is comparable across states. As UAC puts it, "an ATAR of 85.00 in NSW or the ACT is equivalent to an ATAR of 85.00 in other states."
- reports anything below 30 as "less than 30" (the exact label varies by state).
Chemistry on its own never produces an ATAR. Your Chemistry result is one input, combined with your other subjects, then ranked. What differs by state is how many subjects count, how they are scaled, and how the total becomes a rank.
New South Wales: UAC
In NSW, UAC (the Universities Admissions Centre) calculates and releases the ATAR from your HSC results.
The crucial first step is scaling. As UAC states, "your scaled marks, not your HSC marks, will be used to calculate your ATAR." Each course is scaled to account for how difficult it was and how strong the cohort sitting it was, so that results across different subjects can be compared fairly.
Your ATAR is then built from an aggregate of scaled marks in 10 units of study, made up of:
- your best 2 units of English, plus
- your best 8 units from your remaining courses.
Chemistry is a 2-unit course, so a strong Chemistry result contributes to that "best 8 units" pool. The aggregate is then placed on a percentile scale to produce your ATAR. (The full method is set out in UAC's Calculating the Australian Tertiary Admission Rank in New South Wales: A Technical Report.)
The key NSW feature for Chemistry students: English is compulsory in your aggregate, but every other unit competes on scaled marks, so doing well in a well-scaling subject like Chemistry helps.
Queensland: QTAC
In Queensland, QTAC (the Queensland Tertiary Admissions Centre) calculates the ATAR for students completing Year 12 under the QCE system (the ATAR replaced the old OP in Queensland from 2020).
To be eligible for an ATAR, you must complete one of:
- five General subjects (Units 3 and 4), or
- four General subjects plus one Applied subject (Units 3 and 4), or
- four General subjects plus a completed VET qualification at Certificate III level or above.
You must also satisfactorily complete an English subject (a minimum grade of C in English, Literature, or English as an Additional Language). Note the difference from NSW: in Queensland English must be passed to be eligible, but it does not have to be one of the subjects that counts towards your aggregate.
The calculation runs roughly like this:
- The QCAA sends your subject results to QTAC.
- QTAC applies inter-subject scaling, which "adjusts for the fact that it is more difficult to obtain a high result in some subjects than in others."
- Your best five scaled subject results are added together to form a Subject Aggregate.
- Students are ranked by aggregate, then placed into ATAR bands based on the Queensland Year 12 population.
For Chemistry students, the takeaway is that Chemistry is one of your best-five subjects, scaled against every other subject, so its scaled value is what matters, not the raw result alone.
Victoria: VTAC
In Victoria, VTAC (the Victorian Tertiary Admissions Centre) calculates the ATAR using VCE results issued by the VCAA.
Victoria has an extra layer the others do not: the study score. For each Unit 3–4 study, the VCAA reports a study score from 0 to 50, where 30 is the average for every study and the score shows how you performed relative to everyone else who sat it. So your Chemistry study score already tells you where you sit in the state for Chemistry before scaling even begins.
VTAC then scales those study scores and builds an aggregate from:
- your VTAC scaled study score in one of English, English Language, Literature or EAL, plus
- your next three highest scaled study scores, plus
- 10 per cent of your fifth and sixth permissible study scores.
A maximum of six studies contribute, and you need at least four study scores in an acceptable combination to receive an ATAR. The aggregate is then placed on a percentile scale, and, as VTAC states, "aggregates are placed on a percentile scale to produce ATAR from 0 to 99.95."
For Chemistry students, this is the system where your subject result is most visible: your Chemistry study score is one of the (up to six) numbers that build your aggregate, and if it is among your top four it counts at full weight.
The three side by side
| NSW (UAC) | QLD (QTAC) | VIC (VTAC) | |
|---|---|---|---|
| Who calculates it | UAC | QTAC | VTAC |
| Built from | Scaled HSC marks | Scaled subject results | Scaled study scores |
| How many count | Best 10 units (best 2 English + best 8 others) | Best 5 scaled subjects | Best 4 study scores + 10% of 5th and 6th |
| English | Compulsory in the aggregate (2 units) | Must pass (C+) to be eligible | One English study must be in the aggregate |
| Subject-level score reported | HSC mark and band (1–6) | Scaled subject result | Study score (0–50, average 30) |
| Range and increments | 0.00–99.95, steps of 0.05 | 0.00–99.95, steps of 0.05 | 0.00–99.95, steps of 0.05 |
What actually matters for a Chemistry student
Three systems, one practical lesson: you cannot control scaling, so control your result. Scaling, aggregates and percentile ranks all happen after the marks are in and are out of your hands. What you can influence is your Chemistry mark, study score, or scaled subject result, and in every state that result is one of the numbers that builds your rank.
So the strategy is the same in Brisbane, Melbourne and Sydney: maximise your Chemistry result by mastering the content and, just as importantly, by writing answers that earn the marks. That is the part students most often leave on the table.
Avocado is an AI-powered Chemistry tutor with a dedicated mode for the HSC syllabus, the QCE syllabus and the VCE study design. It will not calculate your ATAR, but it helps you lift the one input you actually control: drill the right questions for your system and get specific feedback on exactly where your answers lose marks.
Frequently asked questions
Is the ATAR a mark out of 100? No. It is a rank, not a mark. It runs from 0.00 to 99.95 in steps of 0.05, and it shows your position relative to your age group, not a score in any subject.
Is an ATAR of 90 in NSW the same as 90 in Victoria or Queensland? Yes. ATARs are designed to be equivalent across states, so the same number means the same rank regardless of where you sat Year 12.
How many subjects count towards my ATAR? NSW uses your best 10 units (your best 2 units of English plus your best 8 other units). Queensland uses your best 5 scaled subjects. Victoria uses your best 4 study scores plus 10 per cent of your fifth and sixth.
Does Chemistry "scale well"? Scaling depends on the cohort each year, not a fixed list, and is decided by the relevant authority after results are in. It is not something you can plan around. The reliable strategy is to maximise your Chemistry result; the scaling then takes care of itself.
Do I have to do English to get an ATAR? Effectively yes in all three states, but in different ways. NSW always includes your best 2 units of English in the aggregate. Queensland requires you to pass an English subject (C or higher) to be eligible. Victoria requires one English study score to be included in your aggregate.
Who works out my ATAR? UAC in NSW, QTAC in Queensland, and VTAC in Victoria. The school authorities (NESA, QCAA, VCAA) provide the underlying results; the tertiary admissions centres turn them into the rank.
ATAR methods sourced from the official tertiary admissions centres: UAC (NSW), QTAC (QLD) and VTAC (VIC), plus the VCAA study score definition. ATAR rules are reviewed regularly; always confirm the current method on the relevant centre's website before relying on it.