The cost of putting a child through a 14-year private education in the UK stands at £286,000, research suggests.
It indicates average day school fees are now £13,194 per year and boarding fees cost an average of £30,369.
Private schooling from primary age to A-levels totals £286,000 for a day place and £468,000 for a boarder, the report from Killik and Co finds.
London remains the most expensive region, with an average day school place costing £15,500 per year.
The north of England and Scotland were the cheapest, at £10,400 and £10,700 respectively.
In a survey of 250 parents who privately educate their children, over a third (37.2%) said they saw private education as an "investment priority".
Of those surveyed, 34% said the attraction of smaller class sizes was a major consideration.
Almost a quarter said they sent their children to private school for "the connections my children will get" (24.8%).
Another main reason was that "either myself or a member of my family went there" (18%).
Sarah Lord, managing director of Killik financial planners, said: "The cost of private education is eye-watering for many families. However, over a third of parents responded that investment in education is one of the best investments they can make.
"Of course, private education is not going to be viable for everybody. For some, it will make much more sense to opt for a good state school and invest the money elsewhere.
"Indeed, 14 years of day school fees from 2015 could be invested over this time to build a potential sum of around £800,000, which would help children later on in life, whether that be funding university, buying a house, or securing a comfortable retirement."