A new report has shown the education of a child born in 2017 is expected to cost $38,362, a figure worrying educators and parents.
The Australian Scholarships Group (ASG) Planning and Index said the figure, which covered 13 years of public education for a New Zealand child, had increased by 15 per cent since 2007.
It was estimated state-integrated schooling would cost $109,354 for a child born in 2017, and private schooling would be $345,996.
The data for the index was based on 2000 responses and measured costs including school fees, transport, uniforms, computers and school trips.
ASG chief executive John Velegrinis told NZME the increase in education costs had risen at double the rate of inflation in the past decade.
"This is quite significant because the underlying trend is that this gap between the costs of education and the CPI is continuing to expand over time."
He said digital devices had been the biggest driver to the increased costs for parents.
Labour Party education spokesperson Chris Hipkins said underfunding and the recent funding freeze was "denying Kiwi kids their right to a free schooling".
"If they don't get the money from Government, schools have to look elsewhere and parents are the ones most likely to end up footing the bill. It's as simple as that.
Gate Pa School principal Richard Inder said as a child got older, the price of education went up.
"School isn't free, that's for sure. School fees can go from $0 to quite expensive, and that would apply in Tauranga."
Tauranga Budget Advice manager Diane Bruin said schooling costs were an issue for many parents.
She said the majority of schools had their own schemes where parents could pay off the costs on a weekly basis, or paid in advance before school started to relieve financial burden.
"What is difficult is to have a talented individual at sport or academic that can't be supported in opportunities due to the cost."
PPTA president Jack Boyle said free education was "the cornerstone of a healthy society".
"The irony is that the free education is costing more and more, it needs to be addressed. What is included in 'free education' is a lot of pressure on the parents."
NZEI president Lynda Stuart said the ASG figure was a "real concern".
"We know it's an issue. We already have a freeze on funding, and that really does effect what happens in the school and what resources they can provide."
She said the lack of funding was "disadvantaging those the most vulnerable" through schools having to cut teacher aide hours.
Education Minister Hekia Parata said ASG's research was not representative of the general population of parents, "especially if most of their customers send their children to private schools".
"The Government funds state and state-integrated schools to provide a good public education. This financial year that amounts to over $11 billion in early childhood, primary and secondary education, the highest ever investment in public education."
She said funding for schooling had increased by 35 per cent since 2008/9, while student numbers only increased by 3.6 per cent.
"Our schools are already among the best-equipped in the OECD for digital technology and connectivity."
"Whilst many schools do ask parents to provide a digital device if they can, they will take steps to allow access to school devices for those who can't."
Tauranga parent Maryana Prodger said the $40,000 figure was "unbelievable".
"I've got a 7n-year-old and the school fees are $130 all up, we're very lucky."
However she said she knew of other parents in Tauranga who were having to buy their children MacBook computers.
"On top of the uniform, I can see how costs go up. It's crazy, it doesn't have an impact on us yet but there are parents struggling."
Catherine Hosking said the price increases had not effected her family either.
"My son is in Year 9 and my daughter is in Year 6. One goes to a private school and one to public but I haven't noticed the cost going up. It's not been exorbitant."