HSC ATAR calculator

How this calculator works

The HSC ATAR is calculated by UAC, not NESA. UAC scales each course mark for the academic strength of its candidature, adds your best 2 units of English and best 8 other units into an aggregate out of 500, and converts that aggregate into a percentile rank. This calculator follows the same steps using UAC's own published figures from the Report on the Scaling of the 2025 NSW HSC:

1. Scaling. For each course, UAC publishes the HSC mark and scaled mark at the 25th, 50th, 75th, 90th and 99th percentiles and the maximum (Table A3). We interpolate your mark between those points to estimate your scaled mark per unit.
2. Best 10 units. We take your best 2 units of English, then your best 8 remaining units (there is no Category B limit from 2025).
3. Aggregate to ATAR. We convert the aggregate using UAC's 2025 published points (Tables 3.2 and A9): for example an aggregate of 300 gave an ATAR of 77.40, 350 gave 86.45 and 400 gave 94.40.

What this calculator is not

This is an estimator, not UAC's official tool. UAC notes that one HSC mark can correspond to a range of scaled marks, scaling changes every year, and 2026 results will be scaled against the 2026 cohort. For your official ATAR, refer to UAC.

How to use this calculator

• Estimate from trials. Enter your trial marks to see what your ATAR would be if those marks held in the HSC.
• Plan target marks. Enter target marks and adjust until the estimate matches the ATAR your course needs.
• Test subject choices. Compare combinations to see how scaling changes the estimate for the same marks.

Want to understand the maths in depth?

Read our explainer on how the HSC ATAR is calculated, or on how HSC subjects are scaled.

Common questions

How is the HSC ATAR calculated?

UAC scales each of your HSC course marks, adds up your best 2 units of English and your best 8 other units into an aggregate out of 500, and converts that aggregate into a percentile rank of the notional Year 7 cohort. That percentile is your ATAR.

What is HSC subject scaling?

Scaling adjusts your mark for the academic strength of the students taking each course, so a scaled mark means the same thing in every course. In 2025, for example, a median Chemistry student had a scaled mark of 33.9 per unit while a median Business Studies student had 23.4 (UAC 2025 report, Table A3).

How accurate is this calculator?

It is an estimate. UAC does not publish an exact HSC-mark-to-scaled-mark table, so we interpolate between each course's published percentiles. Checked against the worked students in UAC's 2025 scaling report (for example Fred, 35 per unit in six courses, ATAR 58.10, and Laura, 40 per unit, ATAR 78.10) it lands within about 2.5 ATAR points. Scaling also shifts from year to year.

Is this calculator official?

No. It is an estimator built by ExamExplained from UAC's published 2025 scaling statistics. For your official ATAR, refer to UAC. Use this tool to plan subject choices and target marks.

Why does the calculator require English?

UAC's ATAR requires the best 2 units of English. English Extension units can be among those 2 units if they scale higher, but you must complete a 2-unit English course to be ATAR-eligible.

What about Health and Movement Science?

Health and Movement Science replaced PDH&PE and is examined in the HSC for the first time in 2026, so no scaling data exists for it yet. The calculator uses the 2025 PDH&PE figures as the closest available proxy.