A predicted fall in the number of school children could cost hundreds of teachers their jobs next year.

The Education Ministry has told schools it expects to fund 45,118.4 FTE teachers next year, 351.5 fewer than this year.

The ministry's operations and integration leader Sean Teddy says the figure is based on forecast student enrolments for 2023.

Most of the decline would be in primary and intermediate schools which would lose funding for 355 teachers.

Secondary schools would lose 18.5 FTE positions but specialist schools would gain 16 and composite schools which teach both primary and secondary students would gain six.

Teddy says a reduction in school's entitlement staffing might not mean a school will cut teachers.

"In practice, often schools do not employ all the teachers they are funded for, for a variety of reasons. Some schools may not be able to fill positions, and some may choose to bank the funding and spend it on other things if they are confident that is in the best interests of their students."

The ministry tends to over-estimate staffing so schools can manage big reductions over several years, Teddy says.

The decline in primary schools is largely due to large birth cohorts moving out of that sector and into secondary schools, he says.

Primary principals had been warning of potential cuts and some wanted this year's staffing frozen to help schools cope with pandemic-related pressures.

Principals Federation president Cherie Taylor-Patel says the cut in entitlement staffing is disappointing and will have a big effect on schools that lose teachers.

"We're really disappointed that we've had to lose any teachers out of the system," she says.

"NZPF have been advocating since term one that staffing for 2023 needed to stay the same so that schools can support those students who have lost learning time."

Taylor-Patel says it's likely schools in growing neighbourhoods will lose teachers for the start of next year only to rehire them as more families move into new housing in their area.

Schools could ask the ministry for a review of their staffing entitlement estimates, she says.

-John Gerritsen/RNZ.