Students are missing out on at least a year and as much as four years of schooling by the time they reach year 10, with attendance rates plummeting to as low as 60 per cent in some parts of NSW.

About 470 government schools have attendance rates below 90 per cent, the equivalent of missing one or more year of schooling by year 10, in what researchers say is a concerning downward trend that is affecting academic outcomes and future prospects of disadvantaged students.

Attendance has also been identified as a key concern by the NSW government and is among target areas that all public schools will focus on from next year, alongside wellbeing, equity, literacy and numeracy targets.

"For a student to achieve their educational best and boost their career and life options, ongoing attendance at school is essential," NSW Education Minister Sarah Mitchell said.