Sydney is the most expensive city for parents to send their children to school, but families must also factor in ancillary costs, which are rising many times faster than the annual rate of inflation, a new report finds.

The annual Cost of Education Index found the total cost of educating a child in a private school in Sydney rose by 9 per cent in the past year. The average total cost – fees plus ancillary items – was $411,108 over 13 years. That is 17 per cent above the national average of $350,158, and well ahead of Melbourne ($388,618) and Brisbane ($369,646).