The government committed $5.8 billion to implementing pre-kindergarten for all NSW students by 2030 during the recent budget, a plan that Sarah Mitchell on Tuesday called an opportunity to recalibrate school starting times.

"I actually think it gives us an opportunity in NSW to look at the school starting age," Ms Mitchell told the Centre for Independent Studies.

"One of the concerns that I hear a lot from kindergarten teachers is you're in a classroom with four-and-a-half-year-olds and six-year-olds, because obviously you have to be at school the year you turn six.

"But a lot of parents will send their children early because they can, and overwhelmingly it's not because they're so bright and ready to go.

"It's because it means they don't have to get another year of daycare.

"It means they don't have the extra cost of early childhood."

Ms Mitchell said she hoped for students to begin universal pre-kindergarten in the year they turn five, and that students spend at least one year in pre-kindergarten, attending five days a week.

She said she hopes all students would begin school the year they turn six.

She also hopes students would spend four years in early childhood education.

"That will start them in such a good position compared to some of the different issues that families are dealing with now."

She said there were still nuances to be worked through with the state's schools and early childhood sector.

In NSW currently, children are allowed to begin school at age four if they turn five before July 31 that year.

Children also must legally be in kindergarten before their sixth birthday.

Australian Associated Press