There is no actual maximum in NSW, but there is an agreed upon average:
But, as stated, that is public schools.14. Class sizes
Class sizes will be planned generally on the following basis and will hve regard to the needs of the school:
PRIMARY SCHOOL AND PRIMARY DEPARTMENTS OF CENTRAL SCHOOLS
The statewide average class sizes are 20 in Kindergarten, 22 in Year 1, and 24 in Year 2.
No class need exceed 30 students.