The Australian Scholarships Group has estimated parents of children born in 2018 could fork out $424,844 for 13 years of private schooling, $234,975 for a faith-based education and $50,145 to go through the public system.

The ACT ranked the fourth most expensive jurisdiction in which to give a child an independent education, fifth most expensive for a faith-based system and sixth for government schooling.

The cost of a private education had dropped $22,463 compared to previous analysis.

Researchers surveyed more than 13,500 Australian Scholarships Group members across Australia on costs associated with their child's schooling to reach the figures, including school fees, stationery and extracurricular activities.

Australian Scholarships Group chief operating officer Bruce Hawkins said the cost of education has risen more than double the rate of inflation and outstripped the growth in wages over the past decade.

"The cost of education has soared by 61 per cent compared to the average growth rate in wages of 34 per cent," he said.

"If you have three children, the cost of education at a Canberra private school could top $1.2 million. That's significantly more than the purchase price of the average family home."

But the Independent Schools Council of Australia hit back at the company's estimations, with executive director Colette Colman saying the majority of private school fees were "much more affordable than ASG modelling suggests".

"While ASG admit their school fee figures 'represent the upper ranges that parents can reasonably expect to pay', they neglect to show just how small a proportion of Australia's independent schools are actually charging the kind of fees that could contribute to those sorts of cumulative costs," she said.

"There are numerous ways parents can save on costs, with many independent schools offering scholarships, all-inclusive fees, and discounts for siblings or lump sum payments.

"We would strongly urge parents to do their own research on the fees of schools that interest them."

More than 60 per cent of all ACT students were enrolled in a public school in February last year, with the remainder split almost evenly between independent and Catholic schools.

Analysis released in November showed the government system was gaining popularity among high-income Canberra families.

Australian Education Union ACT secretary Glenn Fowler said: "Study after study has shown that children do at least as well in a public school, and the savings for a family over 13 years of schooling are astronomical.

"Research shows being home more often with your kids and providing them with experiential learning through things like educational holidays are much better bang for your buck."

According to the Australian Scholarships Group, the most expensive place to receive an independent education was New South Wales. Queensland's faith-based schools were Australia's priciest and Victoria's government schools carried the nation's highest bill.

The national averages for 13 years of education were $475,342 in the independent sector, $240,679 in a faith-based system and $66,320 for government schooling.