How ATAR scaling works

Scaling is probably the most misunderstood part of the ATAR. Rumours spread every year about which subjects "scale well" and which "scale badly". This guide explains what scaling is designed to do, how it fits into the ATAR calculation and why choosing subjects purely for scaling is a gamble.

This guide is general information written in our own words, based on the official sources listed at the end. ATAR rules, scaling, dates and course requirements differ between states and change from year to year, so always check with your admissions centre, institution and school. We don't predict ATARs, publish cut-offs or recommend particular schools, tutors or courses.

The problem scaling solves

Senior students can study thousands of combinations of subjects. One student might take advanced mathematics, physics and chemistry; another might take English, visual arts, legal studies and a language. To rank everyone on one scale, admissions centres need a fair way to compare a result in one subject with a result in another. That's what scaling does.

What scaling is based on

QTAC explains that scaling adjusts for the fact that it's more difficult to obtain a high result in some subjects than others. Importantly, it says this isn't because some subjects are inherently harder, but because some subjects attract a more competitive group of students. UAC describes the same principle: courses taken by students with high overall achievement tend to have a higher scaled mean.

In other words, scaling looks at how well the students in each subject perform across all their subjects. If the students in a subject tend to do well everywhere, a given result in that subject is scaled accordingly.

The principle: neither advantaged nor disadvantaged

UAC and QTAC both state the core principle: students should be neither advantaged nor disadvantaged by the subjects they choose. Scaling is designed so that, in theory, your ATAR reflects your overall achievement, not your subject combination.

Scaled marks are often lower

UAC notes that your scaled mark may differ from your HSC mark, and that for most courses your scaled mark will be lower. That's normal and isn't a penalty; scaled marks exist only to calculate the ATAR.

From scaled results to an aggregate

After scaling, each system adds your best scaled results into an aggregate, using its own rules:

• NSW (UAC): an aggregate of scaled marks across 10 units: your best 2 units of English and your best 8 units from your remaining courses.
• Victoria (VTAC): your scaled study score in one English subject, your next best three scaled study scores, plus 10% of your fifth and sixth permissible scores.
• Queensland (QTAC): your best five scaled results from eligible inputs, such as five General subjects, or four General subjects plus an Applied subject or a completed VET qualification at Certificate III or above.
• South Australia and the NT (SATAC): a university aggregate from your best 90 credits of scaled scores.
• Western Australia (TISC): a Tertiary Entrance Aggregate of your best four scaled scores plus 10% bonuses for a language other than English, Mathematics Methods and Mathematics Specialist; TISC gives the maximum as 430.

See our ATAR by state guide for more.

From aggregate to ATAR

Aggregates are ranked, and the ranks are converted to ATARs. QTAC describes placing students in order of merit, working out how many belong in each of 2,000 bands based on the Queensland Year 12 population, then assigning bands from 99.95 down. VTAC describes placing aggregates on a percentile scale.

Scaling changes every year

Because scaling depends on how each year's students perform, scaled results change from year to year. That's why SATAC warns that historical conversion tables aren't a reliable way to predict future ATARs, and why we don't publish predictions or "scaling tables" here.

Choosing subjects

It's tempting to choose subjects you've heard "scale well". The risk is that you end up in a subject you don't enjoy or aren't strong in, and your result suffers. Because scaling aims to be neutral, a strong result in a subject you enjoy usually serves you better than a weak result in a subject chosen for scaling. Other factors matter more:

• Prerequisites: some university courses require particular subjects. QTAC notes that if you haven't completed a prerequisite, you won't be considered for the course regardless of your ATAR.
• Interest and strengths: you'll put in more effort and likely perform better.
• Rules about combinations: some subjects can't both count. For example, QTAC says only General English or Applied English subjects can be included, not both.
• Your plans: subjects can build skills for careers and further study.

Talk to your school's careers adviser before choosing.

The bonus points myth

Bonus points, now often called adjustment factors, aren't part of scaling. QTAC explains that adjustment factors are added to create a selection rank for a particular course and don't change the ATAR. VTAC's subject adjustment points are applied to the aggregate for selection, not to the ATAR itself. See our selection ranks guide.

Where to learn more

Each admissions centre publishes detailed technical documents on scaling and the ATAR, such as QTAC's Calculating the ATAR in Queensland and VTAC's ATAR and Scaling Guide. They're dense but authoritative if you want the full detail. See also our ATAR myths guide.

An everyday analogy

Think of two running clubs. In one, most members are elite athletes; in the other, most are beginners. Finishing in the middle of the elite club's race is a stronger performance than finishing in the middle of the beginners' race. Scaling does something similar for subjects: it considers how strong the group of students taking each subject is, using their results across all subjects, so a result in one subject can be compared fairly with a result in another.

What scaling cannot do

Scaling can't turn a weak result into a strong one, and it can't make up for missing prerequisites. It also can't be predicted precisely in advance, because it depends on each year's students. The best way to benefit from the system is simply to do as well as you can in subjects that suit you.

Try the study planner

Our free study planner shows how many weeks you have until your first exam, splits your weekly revision hours between your subjects and suggests what to focus on in each phase. It also includes a simple selection rank adder for after results. It runs entirely in your browser, nothing you enter is sent anywhere, and it doesn't try to predict your ATAR.

Where our information comes from

Factual statements in our guides are based on official and expert sources, including the Universities Admissions Centre (UAC), the Victorian Tertiary Admissions Centre (VTAC), the Queensland Tertiary Admissions Centre (QTAC), the South Australian Tertiary Admissions Centre (SATAC), the Tertiary Institutions Service Centre (TISC), healthdirect, the Australian Government's movement guidelines and ReachOut. We link to each source at the end of the page and rewrite everything in our own words.

Rules change every year

ATAR rules, scaling, adjustment schemes, key dates and course requirements are reviewed regularly and can change from one year to the next. A rule that applied to an older sibling or a friend in another state may not apply to you. Treat our guides as a starting point, and confirm anything important with your admissions centre, your school and the institutions you're applying to.

Talk to your careers adviser

Your school's careers adviser is one of the most useful people you can talk to in Year 11 and 12. They know your state's system, current key dates, early offer schemes, access schemes and pathways, and can help you plan subjects and preferences. Book a time early, bring your questions and follow up after results.

Key points

• Scaling lets students with different subjects be compared fairly.
• It reflects how competitive each subject's students are, not inherent difficulty.
• Each state builds an aggregate from scaled results using its own rules.
• Choose subjects for interest, strengths and prerequisites, not rumours about scaling.