About two-thirds of Australian students attend public schools, but teachers say that in every jurisdiction except the ACT, government institutions are underfunded.
Officials from the Australian Education Union and other teaching organisations will on Wednesday call on the federal government to increase its funding contribution after research found this would bolster the economy.
A report from the Centre for Future Work found more than 17,000 jobs would be added, yearly GDP gains would grow to $9.9 billion after two decades and the school completion rate would grow by 1.5 to 2.5 percentage points.
"Government effectively 'profits' from fully funding public schools," the report authors said.
"This is money the federal government is quite literally leaving on the table.
"Through its continued underfunding, governments' own revenue position will ultimately be weakened."
About two-thirds of Australian students are enrolled at public schools. (Paul Miller/AAP PHOTOS)
The federal government currently provides 20 per cent of each public school's Schooling Resource Standard - which estimates how much total public funding is required to meet students' needs - while the states contribute 75 per cent, leaving a five per cent shortfall.
In a bid to fully fund every public school, the federal government has offered to increase the Commonwealth contribution to 40 per cent in the NT and 22.5 per cent everywhere else, with the expectation that state and territory governments make up the remainder.
Tasmania, Western Australia and the NT have all accepted, but the other states have refused to lift their contribution to 77.5 per cent.
Australian Education Union federal president Correna Haythorpe says it is "critically important" the federal government increase its spending commitment to 25 per cent and close the funding gap by itself.
"(This analysis) profiles the real costs of a failure to provide a full 25 per cent," she said.
NSW Deputy Premier and Education Minister Prue Car has previously said her state cannot roll out critical interventions at scale without more federal funding.
Her Victorian counterpart Ben Carroll has hit out at the federal government's refusal to further grow public school funding when it supports private schools to 80 per cent of the Schooling Resource Standard.
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