Source: The Conversation (Au and NZ)
Year 12 subject scaling is back in the news with reports Victorian students who scored a perfect Australian Tertiary Admission Rank (ATAR) of 99.95 in 2025 all did the two hardest maths subjects, which scale up.
These subject scaling calculations are regularly criticised and feel unfair to many students.
So how does scaling work and how can it reinforce inequality?
Understanding the ATAR
The ATAR is used across Australia to sort and select students completing their final year of high school for the purpose of entering university.
It’s worth saying upfront that the ATAR is not required for all university admissions, and it is used more by prestigious universities than regional universities. There are many equity-based admission schemes, alternative pathways and enabling programs designed to support young people with lower or no ATAR to access university.
The ATAR is a ranking from zero to a maximum of 99.95.
It is calculated by comparing a student’s achievement in senior secondary subjects against all students in a given age group.
An ATAR of 70 means you’ve ranked higher than 70% of your age group.
ATARs are typically calculated based on year 12 subject results. Which subjects count and how subject results are used varies significantly according to the specific rules of each state’s senior secondary certificate.
What about scaling?
Before subject scores are combined to calculate an ATAR, they are scaled.
Scaled subject results are based on a complicated algorithm that takes into account the academic achievement of each subject cohort (meaning the group of students taking a subject in a given year).
The aim is to make different subject results comparable with each other so that students are not advantaged or disadvantaged by their subject choices. The precise algorithm differs between states but the principle is the same.
At a very simplified level, most systems consider how students in a given subject perform across their other subjects. In general, if students in a subject cohort perform higher than average, the subject will scale up. If they perform lower than average, the subject will scale down.
Scaled subject scores are added together based on state-based rules to form an aggregate score, which is then used to calculate a student’s ATAR.
Let’s look at an example.
In Victoria in 2025 chemistry scaled up and agricultural and horticultural studies scaled down.
If you achieved a raw study score of 30 out of 50 for chemistry that year, this was scaled up to 34. And if you achieved 40 out of 50 for agricultural and horticultural studies – in the top 10% – your score was scaled down to 34.
This is because the students studying chemistry, on average, achieved significantly higher results in 2025 across all their other subjects than the students taking agricultural and horticultural studies.
All the advice from the state ATAR calculation bodies emphasises that ATAR calculations and the scaling that underpins them is to make it fair.
But what does “fair” mean?
Educational inequality plays a part
ATAR calculations aim to be fair in the sense they are meant to be purely data-driven (based on numbers only, not subjective assessments about how difficult a subject is) and applied consistently for all students.
But this assumes a level playing field. Subject scores are presented as neutral representations of a student’s ability, effort and potential.
This ignores the fact we have a deeply unequal education system in Australia.
There are extremely high levels of socioeconomic segregation and huge resource disparities between schools. There are stark funding inequalities between public and private schools, and significant staffing shortages that most severely impact rural and low-socioeconomic schools.
A student at an under-resourced and understaffed public school may, for instance, be less likely to have a teacher who is an expert in their subject, or may sometimes have to make do with no teacher at all (due to staffing shortages).
They will therefore likely need to work harder to achieve the same score as a student at an elite private school.
But the algorithm will treat these students’ results as equivalent.
One thing to ask of any policy is who it’s designed for. ATAR scaling calculations are designed to ensure students who take subjects where the cohort is more competitive (such as chemistry) are not penalised for doing so.
But research shows these students are typically the most advantaged.
Students from low socioeconomic backgrounds are more likely to take subjects where the cohort is less competitive. This means they are more likely to take subjects that scale down, such as agricultural and horticultural studies.
There is also evidence these students are more likely to take subjects and pathways that do not contribute to ATAR calculations (which can include, for instance, some vocational subjects).
These students then receive lower ATARs than their more advantaged peers (or no ATAR at all) and are less likely to go to university.
ATAR administering bodies emphasise that subject scaling calculations are made anew every year.
But although the actual numbers change at a micro level, research shows the overall pattern and order of the subjects that scale high to low remains remarkably consistent.
This creates a hierarchy where subjects such as chemistry are positioned as “better” than subjects such as agricultural and horticultural studies, despite both forms of knowledge being important.
Access matters
Access to subjects is also uneven. Low socioeconomic and rural schools are more likely to offer fewer subjects overall and less likely to teach advanced mathematics.
In Victoria, the subject that scales highest is Latin, which is offered by just a small number of high schools – many of them private or catering to privileged students.
For instance, in 2025, a Victorian student with a raw score of 30 out of 50 in Latin received a scaled score of 46 – a significant scaling up.
We can do better
ATAR calculations don’t create these inequalities on their own, and this is why calculation bodies claim they are fair.
But they do solidify and reinforce existing inequalities. They promote the achievements of those who are already advantaged by the system, at the expense of those who are not.
These inequalities are well recognised in the wider policy landscape. This is why there are so many equity-based admission schemes and alternative pathways.
But we can do better. Rather than developing a complex policy architecture around the ATAR to account for its equity failings, we should transform education systems and policy settings so they are equitable in the first place.
This means starting with the interests and experiences of those least advantaged by our current education system, not those already most privileged.
Kate O’Connor does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.
Original source: https://analysis1.mil-osi.com/2026/09/04/how-does-subject-scaling-work-for-year-12-and-why-is-it-unfair/