Question to the Department for Education:

To ask the Secretary of State for Education, if he will make an assessment of the optimum class size for (a) primary and (b) secondary students to achieve the highest level of attainment.

It is up to schools to decide on class sizes that are consistent with raising attainment and helping pupils to achieve their potential. The exception to this is in infant classrooms, where there is a statutory limit of 30 pupils in each class, with some legal exemptions.

The assessment of the evidence by the Education Endowment Foundation found that the impact of reducing class sizes on educational attainment is low compared to the high cost of doing so. Internationally, John Hattie’s work ranks reducing class sizes at 186 out of 250 influences on pupil achievement.

Despite an increase of nearly 850,000 pupils in state-funded primary and secondary schools since 2010, average class sizes remain low. In secondary schools, the average is 22.3 pupils, whilst the average primary class has remained stable at 26.6 pupils. The average size of an infant class is 26.7. This is slightly higher than in January 2021, when the average was 26.6, but lower than it has been over the course of the last decade. Further information about average class sizes can be accessed at: https://explore-education-statistics.service.gov.uk/find-statistics/school-pupils-and-their-characteristics.