The amount parents pay to put their children through state schools has soared by 40 per cent to nearly pound;15,000 in just four years, according to spending estimates.
Research indicates that the total amount an average family will spend on everyday education costs for a child between the ages of five to 16 has reached pound;14,685, up from pound;9,515 in 2002.
The findings suggest that parents in the UK collectively pay more than Pounds 29 billion on pupils' clothes, transport, lunches and school-related activities such as trips and clubs. The figures, from Norwich Union's "School Sums Index", which are based on spending by more than 1,000 families, indicate that parents will spend an average of pound;1,300 per child in the coming academic year on the everyday costs associated with education.
Transport is the most expensive component, costing pound;301 a year, followed by packed lunches, then school dinners.
The cost of school uniforms is also significant, with parents spending an average of pound;244 on shoes, trousers or skirts, coats, jumpers, shirts and sports kit.
Families appear to be spending more than twice as much on school shoes alone as they are on textbooks.
The Norwich Union study also found that boys cost their parents more than girls because their families needed to spend more on after-school clubs, clothes and tuition.
Simon Quick, a Norwich Union spokesman, said: "Many parents think of state schools as being free but the costs are significant. More than pound;1,000 of parents' money gets spent per child each year just covering the everyday costs of sending our children to school.
"This quickly racks up for families with two or three children and, with an increase of pound;200 per child per year over the past four years, parents need to consider the increasing needs and demands of our children."
The findings follow the start of an investigation by the Office of Fair Trading, which is examining whether Britain's pound;450 million-a-year school uniform market is uncompetitive because of deals in which schools force parents to buy the clothes from specified retailers.
The watchdog has already written to 10,000 state schools requesting details of their arrangements.
The supermarket chain Asda this week launched a "Shop'Em to Stop'Em"
campaign, inviting parents to give them the names of schools which they will pass on to the OFT. But the publicity stunt was criticised by teachers' unions which said it risked damaging relations between families and schools.
The Asda scheme was also criticised by the National Confederation of Parent Teacher Associations. Margaret Morrissey, its spokeswoman, said parents could expect their spending to rise even further over the next four years as more schools provide extended services such as after-school clubs.
"Parents may think they are brilliant, but I don't think many realise yet that they are going to have to pay for them," she said.