The price tag of a private-school education has soared to $360,000 over a child's school career, a new survey has found - almost 10 times the cost of a state school.
The survey by the Australian Scholarships Group (ASG) has found that the expected lifetime cost of a private school education for a child born this year, including uniforms, computers and travel as well as fees, has jumped by $14,000 since last year to $360,074.
In contrast, the lifetime cost of putting a child through the state system has actually dropped by $135 to $38,227, mainly because of cheaper computers.
Sending a child to an integrated school, such as a Catholic school, has become $6600 cheaper, at $102,730.
The contrasting trends reflect higher public spending on state and integrated schools through former National Government initiatives such as Communities of Learning, whereas the state subsidy to private schools has been frozen at $41 million since National increased it by $10 million in 2009.
Independent Schools of NZ director Deborah James said the freeze, combined with rising student numbers, would cut state funding per student in private schools by 3.6 per cent this year.
"With limited government support, private schools have no choice but to increase the burden on parents," she said.
She said private school fees last year ranged from $9150 to $20,460 a year for primary schools, and from about $11,000 to $24,000 for secondary schools.
The ASG survey is based on responses from 300 of ASG's 15,000 NZ members, who mostly start saving through ASG when their children are born and draw down their savings as tax-exempt scholarships for tertiary education or to pay for other educational costs.
ASG members are likely to have above-average motivation and financial ability to pay for extra tuition, computers and other educational resources, so the survey figures may be much higher than actual average costs for all NZ families.
However the survey shows that, even though state schools cannot charge fees, the real cost of educating children can run into thousands of dollars when all the extras are counted.
ASG parents with children in state primary schools paid an average of only $311 in school fees and "donations" last year, but total educational costs of $2160 including extra tuition, sports, music and camps ($884), travel to and from school ($320), computers and software ($286), uniforms and sports kit ($209) and schoolbags, books and stationery ($150).
The main difference between the state, integrated and private sectors was the fees and "donations": $311 in state primary schools, $1715 in integrated (mainly Catholic) schools, and $9815 in private schools.
At secondary level the fees averaged $569 in state schools, $4642 in integrated schools and $20,591 in private schools.
For comparison, Ministry of Education data shows that parents in state and integrated schools paid averages of $170 in "donations" and $237 in fees for "activities" such as sports, music and camps in 2016.
Catholic Education Office chief executive Paul Ferris disputed the ASG figures for integrated schools, two-thirds of which are Catholic.
"Catholic primary school fees are about $500 a year and secondary schools are about $1000 a year," he said.
Only 11 per cent of NZ schoolchildren attend integrated schools and only 3.7 per cent attend private schools, so the ASG sample may have included only a few in each category.
Sector groups could not point to any NZ research on whether the extra costs of private schools are worth it for parents.
School-leavers in 2016 were much more likely to have at least NCEA Level 3 from private schools (87.5 per cent) and integrated schools (75 per cent) than from state schools (49 per cent).
Massey University education professor John O'Neill said schools based on agreed values, either faith-based or socio-economic, "are more likely to provide an environment in which everyone is committed to a common cause".
But he said overseas research showed that achievement differences disappeared after allowing for differences in the children's backgrounds and home lives.
Kiwis pay for more extras than South Africans
Kiwis have to pay for extras that have been paid for through school fees in South Africa, an immigrant family says.
Amanda and Colin Kennedy, who came from South Africa nine years ago, send their two children to the local state school, Conifer Grove School in South Auckland.
Ryan, 10, and Megan, 9, either bike to school or get delivered by their parents on their way to and from work, so the family entered "nil" for travel costs in the ASG survey - much less than families who pay bus fares or drive extra kilometres to get their children to school.
Yet the family still spends about $1000 a year on educational costs for each child.
Conifer Grove requests a "donation" of $250 from each family of two or more children, which the Kennedys say is about the same as school fees in South Africa. But when the Kennedys grew up there, the fees included extra tuition, sports and music.
"We used to put our kids in Kumon for extra maths lessons. That worked out at $300 a month, so we had to stop because we couldn't afford it," Amanda Kennedy said.
"In South Africa, if you need extra lessons they do it at school for you.
"My daughter did gymnastics last year. That's $150-$160 a term [$600-$640 a year] through a club. In South Africa all that stuff is catered for at school, so when the kids are there they can choose what they want to participate in."
This year the family has spent $318 on school uniforms, $100 for shoes, $80 for schoolbags and $60 for stationery to equip the two children for school.
They also paid $150 last year for Ryan to attend a camp in the Hunuas and $400 for a laptop for his homework.
"The teacher sends emails, they have to log in by email," Amanda said.
The family uses Studyladder, an online learning program provided free through the school.
The Kennedys say they are not complaining about the extra costs here.
"We love the area, we love the school," Amanda said. "It's because of education that we basically moved to New Zealand to give our kids a better education."