The average income per child in an independent school in Australia is more than 25 per cent higher than their public school counterparts and nearly 40 per cent higher than those in the Catholic system, new data shows.
The average net income for a student in an independent school was $15,182 in 2011, the most recent year available, surpassing the average $12,034 that is received per child in the government sector and $11,079 that is received per child in the Catholic sector.
The latest financial data and NAPLAN results were made public on the MySchool website on Wednesday, the fourth year the information has been published.
The national average net recurrent income per student across sectors in 2011, which includes public funding, fees and other contributions, was $12,337, up 4.9 per cent on the 2010 figure of $11,757.
The national average figures, provided by the government, did not include a breakdown of what percentage of the funding came from government sources or fees.
School-by-school breakdowns are available on the MySchool website.
For example, independent girls school SCEGGS Darlinghurst had a net recurrent income per student of $27,025 in 2011. The majority of that funding, $24,396, came from parent fees and contributions, while there was $3018 in contributions from state and federal governments, before deductions.
Castle Hill High School, a public school in the north west, had a net recurrent income of $10,496 a student, of which $9704 came from governments, before deductions.
President of the Australian Education Union Angelo Gavrielatos said the Gonski review had highlighted the need for a more equitable funding system.
''The case for funding reform has been made, the urgency has been established,'' he said.
Mr Gavrielatos said the higher proportion of public funding received by public schools reflected the fact they did the ''heavy lifting'' when it came to educating poorer students, indigenous students and newly arrived migrant students, and others who required extra assistance.
''The government school figure reflects the higher cost of education provision and maintenance to schools for low SES students, students with disability and those living in remote and isolated settings,'' he said.
Sydney's other most well-funded schools include Sydney Grammar School, which had a net income of $29,681 a student, St Joseph's College at Hunters Hill, which received $28,646 a student and PLC Sydney, which received $26,617 a student.
In 2011, Ascham School at Edgecliff had a net income of more than $30 million - about $30,000 a student. The school received almost $3 million in state and federal government funding, while more than $25 million came from school fees and parent contributions.
The NSW Association of Independent Schools declined to comment.
Chairwoman of the National Catholic Education Commission Therese Temby said Catholic schools operated ''effectively and efficiently''.
Ms Temby said an income per student that was about 9 per cent or 10 per cent lower than the government system was consistent with previous years.
''In terms of the school funding debate at the moment we really are relying on the government being able to deliver on its promise to deliver a funding increase for all schools,'' she said.
''We certainly also wouldn't want the school funding rules and regulations to change too drastically.''
The MySchool website has received about 5 million hits since it was launched in 2010.
School Education Minister Peter Garrett said while the MySchool data showed improvement in many areas, there were still big gaps in performance between lower socio-economic students and their well-off peers.
The net income figures represent the gross income, minus deductions, which are generally for capital expenditure.