How our numbers work

Community Advantage Index (CAI)

What it is

A percentile describing a suburb, not a mark out of 100 and not a school figure. We rank every Australian suburb the ABS scores and the CAI is where a suburb lands in that queue: a CAI of 90 puts the suburb in the top 10% of Australian suburbs we hold a figure for (14,490 of them); a CAI of 50 means roughly half the country's suburbs sit above it. Wherever we print "top 10%" we have counted the suburbs at or above that value — we never assume the share is 100 minus the score. Below the halfway mark we flip the direction rather than flatter it: a CAI of 10 prints "bottom 9%", counted the same way from the suburbs at or below it — not "top 92%", which reads as praise for a suburb sitting in the most disadvantaged tenth of the country.

Where it comes from

ABS SEIFA 2021 (CC BY 4.0), read at SAL (Suburb and Locality) level — the ABS's own suburb geography. The formula, in full, is the one in scripts/modules/advantage.js: CAI = round(0.7 × IEO_percentile + 0.3 × IRSAD_percentile) where IEO is the ABS Index of Education and Occupation (SEIFA Table 5) and IRSAD the Index of Relative Socio-economic Advantage and Disadvantage (Table 3). Where a suburb has an IEO percentile but no IRSAD one, the IEO percentile stands in for it. Suburbs are joined to schools by SAL name plus state, with the state taken from the first digit of the SAL code. Bands are fixed thresholds: 80+ Higher advantage, 60–79 Above-average, 40–59 Mid, 20–39 Below-average, under 20 Lower advantage.

What it does not mean

It is not ICSEA, and it is not a school figure of any kind. ICSEA is ACARA's index, partly built from private parental data collected on enrolment forms; we hold none of that and never publish ACARA's figures. CAI is not a score out of 100, not a grade, not a measure of teaching, results, facilities or safety, and it is identical for every school in the same suburb — so it can never separate two schools in one suburb.

Limits

Area-level only. A suburb averages over everyone who lives there, and a school draws from more than one suburb, so the match between the two is loose. The ABS suppresses the index for very small or unusual localities, so 14,490 suburbs have a figure and some do not. SEIFA is a 2021 Census product and does not move between censuses.

Area Year-12 attainment

What it is

The share of people aged 15 and over living in the suburb who have completed Year 12 or equivalent. Like the CAI it is an area figure and every school in the suburb shares it.

Where it comes from

ABS Census (CC BY 4.0), aggregated to the same suburb geography and attached to the suburb node in our graph.

What it does not mean

It is not the share of a school's students who finish Year 12, and not a completion or retention rate for any school. It counts adult residents — most of whom finished school decades ago, somewhere else.

Limits

Census vintage, so it lags. It measures the resident population, not the school population; in suburbs with lots of movement in or out the two can differ sharply.

School attendance

What it is

The school's own published attendance rate — the percentage of possible school days actually attended, as the state department reports it.

Where it comes from

State Departments of Education, under their open licences. Of the eight states and territories, only NSW & SA publish this per school in the snapshot behind this build, which is why the column is blank for most of the country. We republish the department's figure unchanged; we do not recompute it.

What it does not mean

It is not a measure of teaching quality, results or behaviour. Attendance is strongly shaped by a school's intake, by remoteness, and by whether it is a special school; a lower rate is not a verdict on the school.

Limits

Two states only, so it cannot be compared nationally. Attendance is compared only within a state, never across a border. The states' series are not the same measure: NSW reports Semester 1 2024, counting students in Years 1–10 only (the national reporting standard); SA reports Semester 1 2023, counting every full-time student, with no year-level restriction. The latest years differ as well. A figure from NSW and a figure from SA must not be compared — the gap between them is partly the difference in what is counted. So every attendance figure on this site is printed with its series (for example "NSW, Semester 1 2024"), and every percentile, value-add and ranking built on attendance uses only schools from the same state. Special schools are excluded from our attendance-based rankings because their attendance is not comparable with mainstream schools.

Attendance trend (vs 2019)

What it is

The change in that same attendance rate since 2019, in percentage points. "+3 pts" means the rate is three points higher than the school recorded in 2019 — for example 88% where it was 85%.

Where it comes from

Derived by us from the same NSW & SA departmental attendance series, comparing the latest published year with 2019 (the last pre-pandemic year). Each school is compared with its own earlier figure in its own state's series, and the "Most improved attendance" list is built separately for each state — attendance is compared within a state only, because the states' series measure different things (see School attendance).

What it does not mean

It is not a growth rate or a percentage change, and it is not a quality signal. A rise is a recovery/engagement signal; it does not say results improved. A school starting from a high base has little room to rise.

Limits

Only exists where a school has a published attendance figure in both years. Pandemic-affected years make the comparison noisy, and boundary or campus changes can break the series without us seeing it.

Value-add (attendance vs area)

What it is

How far a school's attendance sits above or below what its area's advantage predicts — "punching above its postcode". Positive means more students turn up than at schools in similarly advantaged areas.

Where it comes from

Ours. Separately for each state, we least-squares fit attendance against CAI across that state's schools that publish both (NSW: 2,077 schools; SA: 496 schools), then value-add = actual attendance − that state's fitted prediction, in percentage points. Attendance is compared within a state only: a school is measured against the line through its own state's schools, never against a line that includes another state's differently-defined figures, so a value-add from one state must not be compared with one from another.

What it does not mean

It is not an academic value-added measure. It says nothing about learning gain, results or teaching — it is attendance, and attendance alone, compared with a statistical expectation.

Limits

It exists only where attendance exists, so NSW & SA only. The fit is gated per state: a state with fewer than 30 schools carrying both figures gets no value-add at all rather than a number from a degenerate regression (that failure once published "+92 pts vs what its area predicts"), and it never borrows another state's line. A single straight line through one state's scatter is a crude expectation, and special schools are excluded from the ranking built on it.

Destinations (VIC)

What it is

The share of a school's Year-12 leavers who enrolled at university in the year after school, and where published, the share in any "positive destination" (study, training or work).

Where it comes from

The Victorian On Track destination survey, published by the State of Victoria under its open licence. Victoria only.

What it does not mean

It is not a measure of school quality or of how hard students were taught. Destination rates track what leavers chose and what their families could support, and a school with a strong VET or apprenticeship pathway will show a low university figure by design.

Limits

One state. It is a survey with non-response, small cohorts at small schools, and a reference year that may lag. Two schools' figures are only comparable if their cohorts are.

Enrolment growth (~5 years)

What it is

The percentage change in a school's enrolment over 5 years. It is a population and capacity signal, not a popularity one: it tracks how many school-age children live nearby and how many places the school can offer. Growth is not evidence that families are choosing this school — a new estate, a rezoning, a year-level change or a neighbouring school closing move it far more than anything the school does.

Where it comes from

VIC & SA enrolment series published by those departments. Computed by us as (latest − earlier) ÷ earlier, over exactly 5 years ending at each state's latest published census: VIC, FTE, Feb 2020→Feb 2025, counting full-time-equivalent students at the February census, all sectors; SA, FTE, Term 3 2019→Term 3 2024, counting full-time-equivalent students at the Term 3 (August) census, government schools only. A school needs a figure at both ends, and at least 20 students at the start; otherwise it gets no growth figure — we never substitute whatever other years exist. Growth is compared within a state only. The states count different things at different censuses (a February count is not a Term 3 count), so every growth figure on this site is printed with its series and window, and the "Fastest-growing schools" lists are built separately for each state — there is no national list.

What it does not mean

It is not a quality measure. Growth usually reflects housing and population change, a new estate or a closed neighbouring school, far more than anything the school did. Shrinking does not mean failing — it often means the suburb aged.

Limits

Two states. Campus mergers, year-level changes and reporting changes can produce large apparent swings — a renamed or restructured school is followed under its department's number. Small schools show large percentages from small absolute changes.

School score — and why most schools do not have one

What it is

A transparent composite, printed as a mark out of 100 ("School score 72/100"). Each of four signals is first converted to a percentile — area advantage 35 · area Year-12 attainment 25 · attendance 20 · university destinations 20. Three of those percentiles are national; attendance is ranked only within the school's own state (NSW & SA each against their own schools), because each state's attendance series measures something different — see School attendance. Those percentiles are then weighted and averaged, renormalised over whichever signals a school actually has. The 0–100 result is that weighted average of percentiles: unlike the CAI it is not itself a percentile, so a 72 does not mean "ahead of 72% of schools". It is shown only where at least one school-level signal (attendance or destinations) backs it. The directory lets you move those weights yourself.

Where it comes from

Ours, computed from the sources above. The two area signals are the CAI and area Year-12 attainment; the two school-level signals are attendance (NSW & SA) and university destinations (VIC).

What it does not mean

It is not an official rating, not ICSEA, and not a measure of teaching quality — and it is emphatically not a score we are willing to attach to every school. About 72% of Australian schools publish no school-level signal at all. For them the composite collapses into the postcode: across the whole dataset it correlates with the CAI at r = 0.969, and in 55.8% of suburbs with more than one school every school would receive an identical score. Both figures are recomputed from the graph at every build (snapshot 2026-09-25), never quoted from a note. Printing that next to a school's name would be an area figure wearing a school's clothes, so those rows show a dash — deliberately, and permanently.

Limits

Only about 28% of schools have a score, and they are concentrated in NSW, VIC & SA because those are the states that publish per-school data. We also refuse to rank a suburb's schools unless at least two of them carry school-level data; otherwise the list is alphabetical and makes no ordering claim. We also emit no structured-data rating markup of any kind — the star-rating field search engines look for is deliberately absent, because we do not rate schools.

Catchment (enrolment zone) boundaries

What it is

The geographic zone inside which a government school guarantees a place. 5,022 zones are mapped, covering ACT, NSW, QLD, SA, TAS & VIC. The Zone check matches an address by point-in-polygon in your own browser — a zone with a hole in it (one that encircles another school's zone) counts the hole as outside, not inside.

Where it comes from

Each state or territory's own published boundary data, under its own open licence: ACT 2026, CC BY 4.0 · NSW, CC BY 4.0 · QLD 2026, CC BY 4.0 · SA 2023, CC BY 4.0 · TAS 2024, CC BY 3.0 AU · VIC 2026, CC BY 4.0. Addresses are geocoded by OpenStreetMap's Nominatim; the match itself never leaves your browser. Zones are joined to schools by the source's school code where it has one, and by exact normalised name where it does not.

What it does not mean

A mapped zone is not an enrolment decision and not a guarantee. It does not cover non-government schools, selective or specialist entry, sibling and out-of-zone rules, or mid-year boundary changes. Living in a suburb is not the same as living in a zone — streets within one suburb routinely fall into different zones.

Limits

Six of eight jurisdictions. We hold no boundary data for the Northern Territory: it publishes its priority enrolment areas through an address lookup rather than as a dataset we could licence-check. Western Australia does publish boundaries, but under CC BY-NC, which forbids the commercial reuse this site must assume — so we exclude it rather than breach the licence. Vintages differ by state. Always confirm a zone with the school or the department before you act on it.

Accuracy & disclaimer

Data is sourced as-is from third parties and may be incomplete or out of date. Our own indicators — the Community Advantage Index, the School score and value-add — are estimates, not official figures, and not ICSEA. We make no warranty that the site is accurate, complete or available, and to the extent permitted by law exclude liability for any loss arising from its use.

This site is independent and not affiliated with or endorsed by ACARA, the ABS, Jobs and Skills Australia, the CRICOS register, or any Education Department. Catchment maps are indicative: always confirm a school zone with the school or the relevant Department of Education before you make a decision that depends on it.

Every dataset behind these figures, its publisher and its licence are listed on Sources & licences. The full terms are on Terms of use. You can see the metrics in use in the school directory, the rankings and the Zone check.