What is the ideal class size?


8 March, 2023


One question that often arises when speaking to potential families is, “What are the class sizes at Scotch Oakburn?”. The answer is that they vary across the school and within Year Levels because there are a number of factors to be taken into account.

  1. The physical size of the classroom.
  2. Whether the Year Level has a high intake of new students.
  3. The age of the students.
  4. The subject being taught and typical learning activities taking place.
  5. The needs of the students in the class.
  6. Resources available to the teacher and students.
  7. Additional Learning Assistants/adults in the class.
  8. Mandatory staff-to-student ratios.
  9. The access to co-located breakout spaces.

To provide some context to this topic, a recent surveying of independent schools across Australia produced average class sizes for schools of similar socio-economic demographic and fee structures.

For schools similar to Scotch Oakburn, the average class sizes are as follows:

Lower Primary – 25
Upper Primary – 28
Lower Secondary – 28
Upper Secondary – 28
The overall ‘average class size’ was 27.25

At Scotch Oakburn College,
the averages are:

Lower Primary – 20
Upper Primary – 23.5
Lower Secondary – 23
Upper Secondary – 21 in core classes to Year 10

A comparison of class sizes

I also note that in many classes, especially in the younger year levels of Junior and Middle School, there is an additional one and sometimes two adults in the classroom, in the role of Learning Assistants. 


TCE is a very different proposition with class sizes varying greatly

Subjects with very low numbers in the same academic area are combined into the one class to make it feasible to offer a wider range of subjects; however, the largest class size is 22 and the average class size is 13.  

Small is a subjective term.

A common misconception is that small class sizes are better for learning. ‘Small’ is a subjective term and means different things to different people; however, there is a straight-line logic in the assumption that the less students in the class, the more time the teacher can spend with each student in the room.  

What the logic doesn’t take into account is the key element in the learning of the students, being the dynamic that is nurtured by the teacher and created by the variety of ideas, thoughts and voices in the room. At some point, the lack of diversity of thought in a ‘small’ class, hinders the potential development of the rich learning dynamic, or environment, in the room.  

Research tells us that the most influential school-based factor that elicits great learning is the teacher in the classroom. The seminal research of John Hattie (Visible Learning) showed quite clearly that, what he called, Climate of the Classroom is of far greater importance than the number of students in the room.  

At the core of classroom climate is the relationship that the teacher builds with each student, which is a significant ‘moderator’. Marzano’s research in 2000, found that these relationships strongly influence: clarity of purpose; strong guidance; concern for the needs and opinions of others; and a desire to function as a member of a team. 

In conclusion, the ideal class size can be as individual as the students and staff who comprise the class, itself. To reduce the discussion to a single factor, student number, is grossly oversimplifying what is a multi-faceted equation. However, at the heart of the ideal class size is the learning environment that the teacher creates by knowing, valuing and caring for each member of the class.  

If we are going to single out any of the multitude of factors at play, then it is the rapport between the teacher and their students which is the most significant in learning, as it is in any form of inter-related human activity. 

Andy Müller