Home/HSC Scaling
NSW · HSC · 16 subjects

HSC scaling calculators — every subject, real UAC data.

Pick a subject to turn your raw HSC mark into an estimated scaled mark. Every calculator is built on UAC's 2025 scaling report and shows how the subject scales versus the rest of the state.

Built on UAC's 2025 scaling data · updated February 2026

Quick answers

Which HSC subjects scale the highest?

On 2025 data: Maths Extension 2 scales highest, then Extension 1, followed by Chemistry, Economics, English Advanced, Maths Advanced and Physics. Scaling reflects cohort strength across all subjects, not difficulty.

Which scale the lowest?

Typically English Standard, Maths Standard, Business Studies, PDHPE and Ancient History — large, broad-ability cohorts. They can still give a great ATAR if you score near the top.

Do high-scaling subjects guarantee a high ATAR?

No. Scaling only rewards performance. A strong mark in a moderate scaler beats a weak mark in a top one — pick subjects you can excel in.

Choose a subject

All 16 HSC scaling calculators

Ordered by how strongly each subject scaled in 2025, highest first.

Maths Extension 2Scales very high Maths Extension 1Scales very high English AdvancedScales high ChemistryScales high Maths AdvancedScales high EconomicsScales high PhysicsScales high BiologyAverage scaling Legal StudiesAverage scaling GeographyAverage scaling Modern HistoryAverage scaling Business StudiesScales low Maths StandardScales low PDHPEScales low Ancient HistoryScales low English StandardScales low

How HSC scaling works

Every HSC subject is scaled by UAC so marks can be compared fairly across subjects with different cohorts. A subject scales up when its students are strong across all of their courses, and down when the cohort is broader in ability. Your scaled marks — not your HSC marks — are added into your aggregate and ranked to produce your ATAR.

These tools estimate your scaled mark per subject from UAC's Preliminary Report on the Scaling of the 2025 NSW HSC. To combine subjects into a full ATAR estimate, use the NSW ATAR calculator; for the detail on our method, see the methodology page. Studying VCE in Victoria instead? Use the VCE scaling calculators.

HSC scaling — common questions

Which HSC subjects scale the highest?

The strongest scalers are Mathematics Extension 2 and Extension 1, followed by Chemistry, Physics, Economics, Mathematics Advanced and English Advanced. Their median scaled marks sit well above the roughly 25/50 state average, because these subjects attract academically strong cohorts.

Which HSC subjects scale down the most?

English Standard, Mathematics Standard, PDHPE, Ancient History and Business Studies scale down. Their median scaled marks fall below the state average. That reflects the breadth of their cohorts, not how hard it is to do well in them.

Do high-scaling subjects guarantee a high ATAR?

No. Scaling rewards a subject only if you score well in it. A modest mark in a high-scaling subject can scale below a strong mark in a lower-scaling one. The reliable approach is to pick subjects you can score highly in.

What does scaling actually do to my HSC mark?

UAC converts your raw HSC marks into scaled marks (out of 50 per unit) so every subject compares fairly. A raw 90 might scale to the low 40s in a strong subject or the high 30s in a weaker one. Your scaled marks — not your raw marks — build your ATAR aggregate.

Should I choose HSC subjects based on scaling?

Understand scaling, but don't let it drive everything. The best subject is the one you'll perform in and stay motivated by. Use these calculators to see how your expected marks scale, then choose on a mix of strength, interest and scaling.

How do I use these HSC scaling calculators?

Pick your subject. Enter your raw HSC mark, out of 100 (or out of 50 for an Extension unit). You'll see your estimated scaled mark and where you sit in the cohort. Everything runs in your browser — nothing is saved.