International Grammar School vs St Andrew's Cathedral School
A head-to-head comparison of two combined schools in New South Wales, 1.3 km apart, using official ACARA 2025 data. Best value in each row is highlighted.
International Grammar School
Ultimo · Independent combined · K-12
1,224 students · ICSEA 1170
St Andrew's Cathedral School
Sydney · Independent combined · K-12
1,436 students · ICSEA 1189
| Measure | International Grammar School Ultimo NSW | St Andrew's Cathedral School Sydney NSW |
|---|---|---|
| Success Index | 82 Top 10% | 88 Top 5% |
| State rank (type) | #32 of 314 | #5 of 314 |
| National rank (type) | #77 of 1,259 | #17 of 1,259 |
| Sector | Independent | Independent |
| Type | Combined | Combined |
| Year range | K-12 | K-12 |
| Students | 1,224 | 1,436 |
| Girls / boys | 527 / 697 | 595 / 841 |
| Foundation intake | 60 | 34 |
| Year 7 cohort | 103 | 175 |
| Year 12 cohort | 106 | 176 |
| VCE median study score VCAA, latest year | – | – |
| VCE study scores 40+ | – | – |
| 5-year enrolment growth | +4% | +5% |
| ICSEA Average 1000 | 1170 | 1189 |
| ICSEA percentile | 98th | 99th |
| Top SEA quarter | 71% | 76% |
| Bottom SEA quarter | 2% | 1% |
| Students per teacher | 9.7 | 9.3 |
| Teaching staff (FTE) | 126.5 | 153.7 |
| Non-teaching staff (FTE) | 55.2 | 93.8 |
| Language background other than English | 26% | 30% |
| Indigenous students | 2% | 1% |
| Suburb | Ultimo 2007 | Sydney 2000 |
| Council area | Sydney | Sydney |
| Remoteness | Major Cities | Major Cities |
| Website | www.igssyd.nsw.edu.au | www.sacs.nsw.edu.au |
The verdict
- •St Andrew's Cathedral School scores higher on the Success Index (88.4 vs 81.9).
- •St Andrew's Cathedral School has the higher ICSEA (1189 vs 1170), indicating a more advantaged community.
- •St Andrew's Cathedral School is the larger school with 1,436 students compared with 1,224.
The Success Index summarises community advantage, resourcing and momentum from ACARA data. It does not measure teaching quality, results or fit. Methodology.
Free academic assessment
Torn between two schools? Start with your child.
Whichever you choose, a free Success Tutoring assessment shows exactly where your child is in English and Maths and how to get ahead before the next school year.
- Personalised learning plan mapped to the Australian Curriculum
- English & Maths from Kindergarten to Year 12
- Flexible memberships, no lock-in contracts
- Your nearest centre: Success Tutoring Lane Cove
Frequently asked questions
Is International Grammar School better than St Andrew's Cathedral School?
On the Success Index, St Andrew's Cathedral School ranks higher (88.4 vs 81.9 out of 100). The index measures community advantage and momentum from ACARA data, not teaching quality, so visit both schools before deciding.
How far apart are International Grammar School and St Andrew's Cathedral School?
About 1.3 km in a straight line, between Ultimo and Sydney in New South Wales.
Which has the better student-to-teacher ratio?
International Grammar School has 9.7 students per full-time-equivalent teacher and St Andrew's Cathedral School has 9.3.
How do International Grammar School and St Andrew's Cathedral School rank in NSW?
International Grammar School is 32nd of 314 and St Andrew's Cathedral School is 5th of 314 among combined schools in New South Wales on the 2025 Success Index.