Hong Life CalculatorsHow UAC calculates the ATAR aggregate
- Each HSC course mark is scaled (scaled marks are out of 50 per unit, so out of 100 for a 2-unit course).
- The aggregate is the best 2 units of English plus the best 8 units from your remaining ATAR courses – 10 units, maximum 500.
- Courses can be accumulated over five years; for a repeated course only the last satisfactory attempt counts.
- To get an ATAR you need at least 10 units of ATAR courses, including at least 2 units of English, three courses of 2 units or more and four subjects. From 2025 there is no Category A/B limit.
- Aggregates are then turned into ATARs by ranking all students.
2025 aggregate → NSW ATAR (UAC reference points)
| Aggregate (out of 500) | ATAR |
|---|---|
| 450.0 | 99.10 |
| 400.0 | 94.40 |
| 350.0 | 86.45 |
| 300.0 | 77.40 |
| 250.0 | 67.55 |
| 200.0 | 57.20 |
| 150.0 | 46.80 |
Example: English 38 × 2 + Maths Advanced 40 × 2 + Chemistry 39 × 2 + Biology 37 × 2 = 76 + 80 + 78 + 74 = 308, plus the best 2 more units (Business Studies 36 × 2 = 72) = 380, which in 2025 sat between ATAR 86.45 (350) and 94.40 (400).
FAQ
Is the HSC mark the same as the scaled mark?
No. Your HSC mark (out of 100) is set by NESA; UAC then scales each course so that results can be compared across courses. The scaled mark is what goes into the ATAR.
Can a 1-unit course count?
Yes. A 1-unit course counts as one unit and can fill one of your best 8 units if its scaled mark per unit is high enough.
What aggregate do I need for a 90 ATAR?
UAC’s 2025 reference points show 86.45 at an aggregate of 350 and 94.40 at 400, so a 90 sat between the two. The exact cut-off appears in UAC’s full scaling report table.
Sources (checked 10 November 2026): UAC “Report on the Scaling of the 2025 NSW Higher School Certificate” – ATAR rules and Table 3.2 (aggregate to ATAR). Estimate, not an official ATAR.