Every Australian state answers the question “how is atar calculated” with the same five-step machine — results, scaling, an aggregate, a ranking, a rank — and then builds that machine six different ways. This guide walks each state and territory system in turn: which results count, how the aggregate is assembled, and a worked aggregate for every system, computed from the admissions centres’ own published rules. This is how the atar is calculated, state by state.

How is atar calculated? The five steps every system shares

Strip away the state branding and how atar is calculated never changes. First, your senior results are finalised by your state’s curriculum authority. Second, an admissions centre scales them, adjusting each subject so its results can be compared fairly against every other subject. Third, the scaled results are combined into a single aggregate under that state’s counting rules. Fourth, every eligible student’s aggregate is ranked from highest to lowest. Fifth, your position in that ranking is converted into an ATAR between 0.00 and 99.95, in steps of 0.05.

However the question is phrased — how do they calculate atar, how does atar get calculated, how is an atar calculated — the machinery is those five steps. Ask how is an atar score calculated and the answer is identical, because the ATAR is not a score at all: it is the percentile your aggregate earns you. An ATAR of 90.00 means your aggregate placed you ahead of about 90% of the Year 12 age cohort. Everything state-specific lives in steps two and three — the scaling method and the counting rules — which is why a single national calculator can only ever estimate, and why the sections below take the states one at a time.

New South Wales: how is atar calculated NSW?

In NSW, NESA issues HSC marks and UAC calculates the ATAR. An HSC mark for a 2-unit course averages your examination mark with your moderated school assessment mark, out of 100. UAC then scales each course, expressing every unit as a scaled mark out of 50, and builds your aggregate from your best 10 units — which must include your best 2 units of English. The maximum aggregate is 500. Eligibility requires at least 10 units of Board Developed courses across at least four subjects, with no more than 2 units of Category B courses among the 10 that count.

A second common phrasing — how is atar calculated in nsw — has exactly the same answer, worked here in full. Take scaled marks per unit of 44 and 43 in English (87 across the 2 units), 45 and 45 in Mathematics Advanced (90), 42 and 42 in Chemistry (84), 40 and 40 in Economics (80) and 38 and 38 in Modern History (76). The best 10 units are all of them: 87 + 90 + 84 + 80 + 76 = an aggregate of 417 out of 500. UAC does not publish an aggregate-to-ATAR conversion table — the conversion depends on the whole cohort’s aggregates — so an honest worked example stops at the aggregate and treats any ATAR attached to it as an estimate.

Illustrative scaled marks, combined under UAC’s published counting rules. English is compulsory inside the 10 units; the other eight units are simply your best.

Victoria: how is atar calculated VCE students ask about

Victoria runs on study scores. The VCAA issues a study score from 0 to 50 for each VCE subject — a ranking within that subject, with a mean of 30 — and VTAC scales those scores and aggregates them in a fixed shape: your best English-group study score (English, EAL, English Language or Literature), plus your next three best scaled scores in full, plus 10% of your fifth and sixth scaled scores. That is the whole answer to how is atar calculated vce students receive in December.

Worked in full, with real 2025 scaling: raw study scores of 35 in English, 40 in Mathematical Methods, 35 in Chemistry, 35 in Biology and 35 in Psychology became scaled scores of 33, 46, 39, 36 and 34 respectively in VTAC’s 2025 scaling. The primary four — English plus the next three best — give 33 + 46 + 39 + 36 = 154, and the fifth score adds 10% of 34 = 3.4, for an aggregate of 157.4. On VTAC’s published 2025 aggregate-to-ATAR table, 157.4 falls between the 90.00 line (155.19) and the 91.00 line (157.79) — an ATAR of about 90 in that year’s cohort. Note how much of the work scaling did: the raw scores summed to 180, a number that means nothing until each one is re-expressed.

Queensland: five scaled results and the TEA

Queensland’s QTAC works from subject results out of 100. After QTAC’s inter-subject scaling places every subject on a common scale, your best five scaled results are summed into a tertiary entrance aggregate (TEA), and the ranking of TEAs becomes the ATAR distribution. Eligibility requires five General subjects at Units 3 and 4, or four General subjects plus one Applied subject, or four General subjects plus a completed VET qualification at Certificate III or higher — plus a grade of C or better in an English subject, which counts toward the aggregate only if it finishes in your best five.

Worked example: scaled results of 82 in English, 88 in Mathematical Methods, 79 in Chemistry, 85 in Biology and 74 in Modern History give a TEA of 82 + 88 + 79 + 85 + 74 = 408. A sixth subject helps only by displacing the 74 — the five-result rule is the whole game in Queensland, which is why Queensland students feel subject drops differently from Victorians: dropping your weakest subject costs nothing, because it was never going to count.

South Australia: how is atar calculated in South Australia?

SATAC calculates ATARs for SACE students in South Australia and NTCET students in the Northern Territory from a university aggregate out of 90. Stage 2 grades are scaled — a 20-credit subject earns a scaled score out of 20 — and the aggregate is built from your best 90 credits: your three best 20-credit Tertiary Admissions Subjects (60 credits) plus the best 30 credits from the flexible option, which can mix further 20-credit and 10-credit subjects or recognised studies, subject to SATAC’s counting rules. Qualifying requires at least 90 credits of TAS and recognised studies at Stage 2, at least 60 of them from 20-credit TAS or valid subject pairs.

Worked example: scaled scores of 18.4, 17.9 and 17.2 in your three best 20-credit subjects (53.5), a further 20-credit subject at 16.8 in full, and half of a fifth at 15.9 (7.95) give 53.5 + 16.8 + 7.95 = an aggregate of 78.25 out of 90. SATAC converts aggregates to ATARs by ranking the qualifying cohort, so — as in NSW — the aggregate is the last number that can be computed exactly from published rules.

Western Australia and the ACT: bonuses and majors

TISC builds WA’s aggregate — the TEA, out of 430 — from your best four scaled course scores (each out of 100, from a combined score that is half school assessment and half external exam), plus bonuses of 10% of your Mathematics Methods score, 10% of your Mathematics Specialist score and 10% of your best LOTE score. Worked example: scaled scores of 84 in Chemistry, 91 in Mathematics Methods, 78 in English, 80 in Biology and 74 in French give a best four of 84 + 91 + 78 + 80 = 333, plus 9.1 (Methods) and 7.4 (French) in bonuses — a TEA of 349.5.

The ACT Board of Senior Secondary Studies builds its aggregate from continuous, school-based assessment scaled by the ACT Scaling Test: your three best major course scores plus 0.6 of your next best course score. Worked example: majors at 168.4, 161.2 and 155.7, with a next-best course at 148.9, give 485.3 + 89.34 = an aggregate of 574.64, which UAC then converts to an ATAR against the percentile framework it also uses for NSW.

How to calculate atar score for international students

The dedicated question — how to calculate atar score for international students — has a different answer, because there is nothing to calculate: you do not convert your results yourself. If you completed an overseas secondary qualification, the admissions centre for the state you are applying in (QTAC, UAC, VTAC, SATAC or TISC) assesses it against Australian Year 12 standards and assigns it a rank comparable to an ATAR, using published conversion schedules and, for qualifications from many countries, long-standing assessment tables. IB Diploma students are handled the same way: the admissions centres convert the IB score to a notional ATAR through a schedule published for each admission year, so IB and ATAR students are ranked together. The practical steps are to apply through the relevant centre, supply certified results when asked, and let the conversion happen inside the assessment — any website offering to convert your overseas grades into an exact ATAR is estimating at least as loosely as the state calculators do.

Estimating your own: how to work out atar score from an aggregate

If you want to know how to work out atar score estimates for yourself, work backwards through the five steps: predict your results, apply the most recent published scaling you can find, build the aggregate under your state’s rules, and compare it with any published aggregate table (VTAC publishes one each year; the other centres largely do not). Students also search “how to work out a atar score” — the method is the same, and its limits are the same too: scaling and the conversion are recalculated from the real cohort each year, so an estimate is a range with a method behind it, not a result. The ATAR Calculator runs the simplified best-four version of this process instantly; the state sections above are how you sanity-check what it tells you. And when you compare your estimate against courses, compare it with the lowest selection rank each course publishes — the rank, after adjustments, of the lowest-ranked applicant who received an offer — not with a rumoured “cut-off”, because selection ranks, not raw ATARs, are what universities select on.

Sources and method: counting rules and eligibility from the admissions centres’ published methods — QTAC and the QCAA (Queensland), VTAC and the VCAA (Victoria), UAC and NESA (NSW and the ACT), SATAC and the SACE Board (SA/NT), TISC and the SCSA (WA), and the ACT BSSS. VCE scaling values and the aggregate-to-ATAR lines are from VTAC’s 2025 Scaling Report (published 11 December 2025), the most recent published at the time of writing. Worked aggregates use illustrative inputs combined strictly under each system’s published rules; only VTAC publishes an aggregate-to-ATAR table, so the other systems’ examples stop at the aggregate. Estimates only — official ATARs are issued solely by the state bodies.