By the time a baby born in 2015 graduates from high school, many parents who choose private schools will have spent more than half a million dollars on their child's education, a new study has found.

The Australian Scholarships Group's modelling released on Tuesday forecast the cost of private schooling in Sydney to be $541,275, making it the most expensive city in Australia to educate a child.

Every chance: Daniella Di Santo with daughters Sienna, 5, and Verona, 3. Credit:Sahlan Hayes

The breakdown is $175,109 for primary school and $359,043 for high school.

Even sending a child to a public school could cost up to $71,000 in Sydney, while parents would spend up to $234,887 for their child to attend systemic Catholic schools.