One-fifth of children not ready for school

More than one in five children in Australia aren't socially, emotionally or academically ready for school, a new report says.

Girls are better prepared than boys, according to the federal government's triennial snapshot of 300,000 children in their first full-time year of school.

More than 15 per cent of girls are considered developmentally vulnerable, compared with 28 per cent of boys.

Nearly 85 per cent of all children are hitting language and cognitive skills targets.

Aboriginal children are almost two-and-a-half times more likely to be socially, emotionally or academically vulnerable than their peers but this trend is declining steadily.

The Australian Education Union says the report highlights the need for Gonski funding.