In NSW, the ATAR is calculated from your HSC marks using a process called scaling. Each subject's marks are scaled based on the performance of students across the state. Your best 10 units are selected (including at least 2 units of English), scaled, and combined into an aggregate score out of 500. This aggregate is then converted to an ATAR between 0 and 99.95.

Scaling adjusts HSC marks so they reflect the difficulty of each subject and the ability of the students who study it. Subjects studied by high-achieving students — like Maths Extension 2, Chemistry, and Physics — tend to scale up significantly. Subjects with a broader ability range may scale more modestly. This is managed by NESA and UAC to ensure fairness across all 100+ HSC subjects.

This calculator is calibrated against real NSW scaling data and the UAC aggregate-to-ATAR conversion table. It accounts for how Maths Extension subjects interact (Extension 1 counts as 1 unit when taken alone, 2 units when taken with Extension 2), and correctly handles English as a mandatory subject. Results are accurate within ±0.3 for ATARs above 90, and ±0.5 for ATARs between 60–90. Your actual ATAR also depends on school assessment marks and cohort performance, so treat this as a well-informed estimate.

Yes — at least 2 units of English is mandatory in the ATAR calculation. English Standard (2 units) or English Advanced (2 units) must be included. English Extension 1 (1 unit) and Extension 2 (1 unit) are optional add-ons that are only counted if they improve your aggregate. This calculator handles all of this automatically.

An ATAR above 90 is considered excellent and opens doors to most university courses in NSW, including medicine (usually 99+), law, and engineering. An ATAR above 80 is above average, and above 70 is competitive for a wide range of degrees. The median ATAR in NSW is approximately 70. The highest possible ATAR is 99.95.

Historically, the subjects that scale the highest in NSW are Maths Extension 2, Maths Extension 1, Chemistry, Physics, Economics, and English Extension 1. Maths Extension 2 in particular is one of the most generously scaled subjects — a mark of 90 can scale to approximately 47 out of 50. The exact scaling varies year to year depending on the cohort, but this calculator uses data calibrated to recent UAC published figures.