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What is ATAR and how is it Calculated?

  • Writer: Andy Li
    Andy Li
  • Oct 18
  • 6 min read

If you’re a high school student (or parent) trying to make sense of the ATAR, it can seem complicated at first. But underneath all the fancy wordings, it’s basically a ranking. We recommend reading the rest of the article for the specifics,


but here's a really quick summary:


Every student receives a "Study Score" out of 50 for each VCE subject they complete. All of these scores are added together to a big number called the student's "aggregate". Every student's aggregate is ranked using a percentile system from 0-99.95 using a fancy formula. If a student's ATAR is 75, they more or less outperformed 75% of their age group.


This article contains the following:

  1. What the ATAR is (and what it’s not)

  2. The steps in its calculation, including scaling, aggregates, and rank assignment

  3. How many subjects count and how much “weight” each subject has

  4. Some caveats and tips


1. What is the ATAR?

2. How the ATAR is calculated: steps in the process


Here is a breakdown of how your ATAR is determined (Victoria / VCE case). The steps are:


Step A: Earn raw study scores

Step B: Scaling (adjusting study scores)

  • Not all subjects are equal in difficulty or competition. To ensure fairness, VTAC applies scaling to every study score. That means a raw score may be adjusted upward or downward depending on how “strong” the cohort was, how many students took that subject, and how their performance compared with performance in other subjects. SW Education+3vtac.edu.au+3Matrix Education+3

  • The idea is to make a score of, say, 30 in one subject represent a similar standard of achievement to 30 in another subject, after adjusting for cohort strength. vtac.edu.au+2Matrix Education+2

  • There are additional special rules (for example, among mathematics subjects, or language subjects) to keep things balanced. Wikipedia+2vtac.edu.au+2


After scaling, each subject gives you a scaled study score.



Step C: Selecting which scaled scores to use (the “aggregate”)



Step D: Converting aggregate to an ATAR (ranking among all students)

  • Once every student’s aggregate is computed, VTAC orders (ranks) all aggregates in descending order (highest to lowest). Matrix Education+3vtac.edu.au+3Matrix Education+3

  • Then each student is assigned a percentile rank corresponding to where their aggregate falls in that distribution. That percentile rank is the ATAR (with some smoothing / interpolation). Matrix Education+3Wikipedia+3vtac.edu.au+3

  • The highest aggregates correspond to the top ATARs (e.g. 99.95, 99.90, etc.). vtac.edu.au+2Matrix Education+2

  • Because of the way percentiles work, ATARs rarely (if ever) are evenly spaced by raw aggregate differences; small differences in aggregate can sometimes shift your ATAR more or less depending on how crowded that part of the distribution is. Wikipedia+2Matrix Education+2


As a result, your ATAR shows how many students you outperformed, rather than how “many marks” you scored.


3. How much does each subject “count”?

Because only four subjects are counted fully, and the 5th and 6th are counted at 10%, not all your subjects influence equally. Here’s a rough “percentage contribution” perspective:

  • The English subject is 100% counted (i.e. full scaled value).

  • The next three best subjects (outside English) are also counted 100%.

  • The 5th subject contributes only 10% of its scaled score.

  • The 6th subject also contributes only 10%.

So in effect:

  • Fully counted subjects (4 of them) – these form the bulk of the aggregate

  • 5th and 6th provide small “bonus” increments

For example, if your four best scaled subjects average 35 each, that contributes 4 × 35 = 140 toward the aggregate; then if your 5th and 6th scaled scores were 30 and 32, their 10% contributions give +3.0 and +3.2, so total +6.2 extra.

Thus, those extra subjects only contribute a modest fraction, but that extra fraction can sometimes make the difference in small ATAR jumps.

Putting that into “percentage” language is a bit approximate, because in one cohort the spread of scores is what matters. But you could think:

  • ~ 90–95 % of your aggregate comes from your “primary four”

  • ~ 5–10 % from your 5th/6th (if present)

Keep in mind: the more you do well in your top four, the more influence those have. The increments are like small boosters.


4. Example

(Adapted from standard examples in VCE guides)

Suppose a student has scaled scores as follows:

Subject

Scaled Study Score

English (chosen from English group)

36.0

Biology

45.0

Psychology

44.0

Business Management

42.0

Legal Studies

39.0

Health & Human Development

38.0

Here’s how the aggregate would be computed:

  1. English (36.0) is included.

  2. Next best three: 45.0, 44.0, 42.0

  3. Fifth best: 39.0 → 10% = 3.9

  4. Sixth best: 38.0 → 10% = 3.8

So aggregate = 36.0 + 45.0 + 44.0 + 42.0 + 3.9 + 3.8 = 174.7

That aggregate is then compared to all students’ aggregates, and the equivalent ATAR is assigned (for instance, maybe 174.7 maps to ATAR ~ 95.80, depending on that year’s distribution).

Note: The exact mapping from aggregate to ATAR changes year to year. Matrix Education+3deakin.edu.au+3Matrix Education+3


5. Caveats, special rules, and tips

  • Because scaling depends on cohort strength (cohort meaning students in their school and year level), two students with identical raw scores might get different scaled scores (if their subject cohorts differ). vtac.edu.au+2Matrix Education+2

  • In mathematics subjects (e.g. General Mathematics, Mathematical Methods, Specialist Mathematics), there are internal adjustments among those maths subjects to avoid penalising students who take tougher maths. Wikipedia+2vtac.edu.au+2

  • In language (LOTE) subjects, sometimes further adjustments are made (e.g. adding “increments” up to +5) under certain conditions. Wikipedia+1

  • If your English scaled score is not among your top four by raw ranking, it still must be included (and if necessary another subject is “demoted” to be a 10% increment) so that English is always counted. deakin.edu.au+2Matrix Education+2

  • If you don’t complete four scored subjects (or don’t have an English subject), you cannot qualify for an ATAR. vtac.edu.au+2Matrix Education+2

  • Doing more than six subjects doesn’t necessarily help much (only top six count, and only the 5th/6th at 10%). deakin.edu.au+2Matrix Education+2

  • Because of the ranking / percentile nature, small differences in aggregate near “crowded” parts of the distribution may produce larger or smaller jumps in ATAR.

  • Finally, your ATAR is only part of university admissions. Many courses also require subject prerequisites, interviews, portfolios, or other criteria.


The team at Academic Peak Tutoring hopes this article helped build your understanding of the ATAR system and answered any questions you might have.


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Written by Andy Li,

18th Oct, 2025


On behalf of the Academic Peak Tutoring team.

 
 
 

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