The aggregate uses 10 units
In NSW, the ATAR aggregate is based on scaled marks across 10 units of eligible HSC courses. It includes your best two units of English and your best eight units from your remaining eligible courses. If you have more than 10 eligible units, the remaining marks do not all get added to the aggregate.
This is a rule about which scaled marks contribute to the calculation. It does not mean that the other HSC courses disappear from your record or have no educational value.
UAC: how the best 10 units are selected · Why your ATAR is not your average HSC mark
Eligibility is separate from which units make the best 10
To receive a standard NSW ATAR, you must satisfactorily complete at least 10 units of HSC courses, including 10 units of Board Developed courses, 2 units of English, at least three Board Developed courses worth 2 units or more, and courses across four subject areas. These eligibility rules are separate from the 10 units selected for the aggregate.
A course and a subject area are not always the same thing: several English or mathematics courses can still belong to one subject area. Some extension and accumulated courses also have specific rules, so check UAC’s current eligibility guidance and your school’s course advice if you are unsure whether your pattern qualifies.
Worked example: selecting 10 units from 12
This is a hypothetical selection example, not a forecast or a scaling conversion. Assume a student satisfactorily completes six eligible 2-unit courses: English Advanced, Mathematics Advanced, Chemistry, Physics, Economics and Biology. This pattern contains 12 units across six subject areas.
For this example only, give each unit in a course the following scaled mark out of 50. These invented numbers are already scaled marks, not the HSC marks on a results notice.
- English Advanced: 30 per unit, contributing 60 across 2 units.
- Chemistry: 42 per unit, contributing 84 across 2 units.
- Mathematics Advanced: 40 per unit, contributing 80 across 2 units.
- Physics: 39 per unit, contributing 78 across 2 units.
- Economics: 38 per unit, contributing 76 across 2 units.
- Biology: 35 per unit, contributing 70 across 2 units.
Why English counts in that example
The 2 English units contribute even though their scaled marks are lower than Biology’s. Of the remaining 10 units, the best eight are Chemistry, Mathematics Advanced, Physics and Economics. The selected aggregate is 60 + 84 + 80 + 78 + 76 = 378 out of 500. Biology is left out of this aggregate, but remains part of the student’s HSC record.
An aggregate of 378 is not an ATAR of 75.6. An ATAR depends on the aggregate’s position in the relevant year’s ranking process. Adding extension courses makes unit selection more involved, so this example deliberately uses only 2-unit courses.
How to check your own course pattern
List each course, its unit value and whether it is an eligible ATAR course. Confirm that your pattern meets the eligibility requirements, then identify the two English units and compare the remaining eligible scaled marks to see which eight units contribute. Extension courses and completed courses from different years have specific rules, so use UAC’s current course information rather than assuming every unit is interchangeable.
Sources and editorial notes
Founder of ATAR Forecast. These guides explain school ranks, HSC results and the assumptions behind the forecasting tool, with links to NESA and UAC sources. These guides explain the process; NESA and UAC remain the official authorities.
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