Half of middle-income parents believe they don't have enough money for their children's schooling, as experts warn of the growing costs of modern education going unmet by the state.
The survey, from an inaugural ASG Parents Report Card including 350 Kiwi parents, found that 83 per cent of parents would like more money to spend on their children's education.
Extra-curriculars or tutoring was too expensive for 44 per cent, while 20 per cent said at least one parent worked two jobs to support their children's learning.
"This includes more than school fees. It's about travel, books, uniforms, laptops. The things that play on parents' minds," said John Velegrinis, CEO of ASG.
The results, compiled by Australia's Monash University, follow concerns from experts that education in New Zealand is now heavily reliant on private funding, with middle-income families struggling to keep up, while lower-income families miss out.
"Our Education Act guarantees a free education, but no one believes that is true any more so the Government need to stop repeating that mantra," said former Secondary Principals' Association president Patrick Walsh.
"People have recognised if you want a 21st century education it is very expensive, and the Government doesn't have the money to provide it.
"If people want more than a basic education, and most do, parents have to pay the additional cost."
Mr Walsh said the funding model - which Education Minister Hekia Parata wants to review - created a divide, where schools that had more money had a clear advantage.
They could prescribe laptops as stationery items. Music, sport, even extra teachers were provided for through fees or partnerships, he said.
Meanwhile, other schools had rundown buildings, not enough teachers, large classes, little technology and hungry kids.
"It's a critical storm of Third World education in New Zealand. And the irony is that education is supposed to be the great leveller in society."
Education professor John O'Neill, from Massey University, said charities, private partnerships and international student fees were now making up the gaps because the Government refused to raise taxes to pay the difference.
Professor O'Neill said there was increasing pressure on parents - for donations, for tutoring to ensure students are ahead, and for saving schemes such as those offered by ASG, a mutual savings society - to top up the costs of education with the belief it was the only way to get ahead.
"The survey is actually a very interesting case of how the private sector is able to make large amounts money from the systematic withdrawal of the state from free, universal public education," he said.
Secondary Principals' Council chairman Allan Vester said while there was a shortfall in funding, the definition of a "normal" education had also changed.
"Outdoor education, for example, is very costly and Government funding was never calculated to fund that," Mr Vester said, adding things like BYOD (bring your own device), uniforms and sports kits also added pressure.
Mr Vester, among others, was calling for a more targeted approach to school funding, replacing the decile system to create more equity.
The Education Ministry said many of the costs included in the ASG survey went beyond the core costs required by parents to participate in a state education.
Schools were not allowed to charge for the cost of teaching or learning, including the materials used in the provision of the curriculum.
"They may, where appropriate, ask parents to meet the costs of materials where there is a clear take-home component. But a student or their family is never obliged to buy anything produced at school," said deputy secretary Ruth Shinoda.
State schools were able to employ extra staff from privately raised money, such as a charity or school fundraising activities, she said.
Education Minister Hekia Parata was unavailable for comment.
ASG Parents Report Card 2015
•83% of parents would like more money to support their children's education.
•44% could not afford after-school tutorials or other extra-curriculars.
•20% of parents said they needed to work two jobs to support their kids' learning.
•33% earning less than $48,000 thought they had enough for their child's needs, compared with 45 per cent of families between $48,000 and $96,000 and 63 per cent of those earning $96,000. Average NZ household income is $85,000.
• 89%thought their teachers were very capable.
•85% want to better understand the school curriculum and teaching methods.
Long hours help girls get ahead
Matt and Yogi Patel work 14 hours a day, 7 days a week to give their daughters the best start in life - meaning they shell out a fair bit on education.
The couple from the North Shore own the Narrow Neck dairy and have lived in the house behind it for 10 years.
Their two daughters, Arpita and Paayal, are in Years 7 and 9 respectively, with Paayal about to sit her first set of exams.
"At the primary level, the money is okay. At secondary it's okay if you have one child there.
"But if you have two or three at secondary then it can be a bit difficult," Mr Patel said.
"They go to public school but we still have to pay the donations, activity fees, fundraising, sports, and they recently started doing school discos. If you add everything up it becomes hard."
Mr Patel said despite the costs he was satisfied, although Paayal wanted to go to Hawaii on a school trip next year so that might require some careful planning.
"But that's why we work hard, for them - that's the only reason."