The Australian Scholarships Group (ASG) study found education costs increased as children got older, with preschool years typically costing $650 a year and primary school years costing $2190 at a government school, $3451 at a Catholic school and $7560 at a private school. Costs to send students to high school ranged from $4,024 a year at a government school, $6,760 at a Catholic school and $9,482 at a private school.

Students in tertiary education cost about $18,750 a year, the study found.

The ASG study asked parents to estimate annual costs for their children's schooling and education and to keep a diary to track expenditures, with expenses for 198 children recorded. It found families assessed essential expenditures differently with some not including costs for transport and lunches and others keeping detailed records.

He said while there was generally a strong correlation between sending children to a public or private school and family income, there were instances of relatively high income families preferring government schools and families with modest incomes sending their children to private schools.