Independent co-ed combined school (PP–12) in outer regional Kalgan, WA; 611 students.
NAPLAN in line with national year-level averages; the result is a B overall.
Great Southern Grammar School is also known as GSGS and GSGS Kalgan.
Great Southern Grammar School has an overall SchoolRank score of 58.5/100, rated "Average". This score is calculated from academic results, student growth, wellbeing, extracurricular programs, and value for money. Academically, the school grades B (Average) against other Australian schools. The school's ICSEA (Index of Community Socio-Educational Advantage) is 1080, well above the national average of 1,000.
In 2025 NAPLAN testing at Great Southern Grammar School, Year 3 students averaged 398 across the tested NAPLAN domains, in line with the national average of 407 for that year level, and Year 5 students averaged 488, in line with the national average of 490 for that year level, and Year 7 students averaged 564, above the national average of 540 for that year level, and Year 9 students averaged 590, above the national average of 569 for that year level. Relative to national year-level averages, the school's strongest domain is Reading. National averages are specific to each year level, because NAPLAN scores are scaled so older year levels score higher, a school-wide average can't be compared with a single national figure.
Great Southern Grammar School is a medium-sized Independent combined school with approximately 611 students. It offers education for years PP-12. As an Independent school, enrolment typically involves an application process. Contact the school directly for enrolment criteria, waiting lists, and open day information.
Great Southern Grammar School has a student-to-teacher ratio of 11.2:1. This is below the national average of approximately 14:1, meaning students generally receive more individual attention. Support staff make up 42% of the workforce, providing additional learning assistance and pastoral care. The student attendance rate is 91%, which is moderate.
Great Southern Grammar School is located in Kalgan, WA, classified as a outer regional school. With an ICSEA of 1080 (78th percentile), the school community's socio-educational advantage is above average, families tend to have higher education and income levels. ICSEA measures the educational advantage of a school's community, not the school's quality, a lower ICSEA school with strong academic scores may indicate particularly effective teaching.