Ministers from all states and territories met with federal Schools Minister Peter Garrett in Sydney on Thursday to discuss overhauling the school funding system.

The Gonski review, released in February, recommended governments inject at least an extra $5 billion a year into schools.

It also proposed a new funding model to cover all schools, public and private, that would give a basic level of funding per student plus extra amounts to compensate for disadvantage.

David Gonski, who authored the review, was on hand to answer ministers' questions about his report's recommendations and explain his rationale.

Mr Garrett said the meeting was not the right time to put a dollar figure on the reforms.

``Let's not continue to get caught in a debate about how long is it going to be before you see what the dollar figure is,'' Mr Garrett said.

``We need to put the horse in front of the cart.''

A senior education department official will develop a high-level road map policy for the education ministers to review in June.

Mr Garrett said his department would aim to have a piece of legislation drawn up by the end of the year but warned there was a ``great deal of work'' to do.

``What we need to now do is to ensure that we can agree and work through a proposed funding model, once we've done that work then we'll consider issues of resources and funding as we should,'' Mr Garrett said.

He said the states needed to come on the ``journey of reform''.

New South Wales Education Minister Adrian Piccoli said the bottom line was worrying most states.