Part 3: How ATAR is Calculated

Your ATAR is determined by converting the sum of scaled marks in 10 units of ATAR courses. Read this guide to learn how your subject choices affect your ATAR.

how is atar calculated

Calculation of Your ATAR

The final step in the determining your ATAR is converting your scaled marks into an aggregate and percentile. The percentile rounded to the nearest 0.05 is your ATAR.

Once the scaling of your HSC marks is completed by UAC, they will use your scaled marks to determine the aggregate. You can see the scaling of different HSC courses in Part 2: Scaling of HSC Marks of this guide.

Calculation of Your ATAR

Flowchart: How Your ATAR is Calculated


The aggregate is the sum of scaled marks in 10 units of ATAR courses.

  • It comprises of your best two units of English and the best 8 units from your remaining units.
  • It is out of 500 as each unit is equal to 50.

The calculation of the aggregate will make more sense if we look at the example below. Let’s look at the step-by-step process of calculating an ATAR.

Step 1: Determine your aggregate from scaled marks

Consider a student with the following ATAR courses shown in the table below.

Table: Aggregate of Scaled Marks
 Subject Units HSC Mark Scaled Mark
English Advanced 2 86 74
Mathematics Advanced 2 94 86
Business Studies 2 88 76
Chemistry 2 90 88
Modern History 2 89 80
History Extension 1 1 46 42
Aggregate 397/500

Based on the rule of determining the aggregate:

    • 2 units of English must be counted regardless of how low the scaled mark is.
    • Only 1 unit of Business Studies course (scaled mark of 38) will be counted towards the aggregate since it has the lowest scaled mark.


Step 2: Convert your aggregate into percentiles

Percentiles indicate the ranking of students in relation to other ATAR-eligible students and are determined on the basis of the aggregate of scaled marks. The percentile corresponding to a particular aggregate is the percentage of the ATAR cohort who received an aggregate mark less than or equal to that aggregate.

Step 3: Convert Percentiles into ATAR

The final step is to determine what the percentiles would have been if all students in their Year 7 cohort completed Year 12 and were eligible for an ATAR. These percentiles are rounded to the nearest 0.05. These are your ATARs.

The table below shows the ATAR at various percentiles for the 2014 through to 2016 cohorts.

Table: ATAR percentiles, 2014 – 2016 (Source: 2016 Scaling Report by UAC)
 Percentile ATAR 2016 ATAR 2015 ATAR 2014
100 99.95 99.95 99.95
99 99.40 99.40 99.35
98 98.75 98.75 98.75
95 96.95 96.95 96.95
90 93.95 93.95 93.95
85 90.90 90.90 90.90
80 87.85 87.85 87.85
75 84.75  84.75 84.80
70 81.60  81.65 81.70
  • Each ATAR corresponds to a range of aggregate of scaled marks.
  • Remember, the number of students with each ATAR varies from year to year with cohort size.

The table below shows the lowest aggregate of scaled marks corresponding to each of the selected ATARs.

Table: ATAR percentiles, 2014 – 2016 (Source: 2016 Scaling Report by UAC)
 ATAR Lowest aggregate
2016 2015 2014
99.95 476.6 478.1 475.3
99.50 455.8 457.9 454.0
99.00 446.0 446.9 444.5
98.00 431.2 432.4 431.2
95.00 403.8 404.2 404.4
90.00 371.7 371.2 372.2
85.00 345.3 343.8 345.1
80.00 320.6  319.9 320.6
75.00 297.5 297.0 296.9
  • The lowest aggregate is the minimum sum of your scaled marks required to receive that ATAR.
  • For example, in 2016 students required the lowest aggregate of 476.6 to receive an ATAR of 99.95, whereas in 2015 students required 478.1.

Matrix ATAR Calculator

You can estimate your ATAR using HSC marks with the Matrix ATAR calculator. Below is an example of an ATAR calculation with a HSC mark of 90:

ATAR Calculation

The Matrix ATAR Calculator


Want to Maximise Your ATAR?

© Matrix Education and, 2017. Unauthorised use and/or duplication of this material without express and written permission from this site’s author and/or owner is strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given to Matrix Education and with appropriate and specific direction to the original content.



Get free study tips and resources delivered to your inbox.

Join 27,119 students who already have a head start.