Research by Santander Credit Cards also claims the cost of keeping under 18s across the UK in school once term begins totals £447m per week.
This works out at roughly £44 per school child per week and includes everyday costs such as packed lunches, bus fares, school trips and after-school activities.
Costs have risen significantly compared to last year, when the average parent spent £177 in preparation for the new school year – an increase of 27%.
Weekly costs are also up 13% since last year, when keeping a child in school cost around £39 per week.
Excluding private education, parents with children at grammar schools spend the most, at an average of £284 in the run up to school term plus an additional £68 per week.
This is followed by parents of children attending foundation and trust schools who spend £276 getting ready for term time and £60 on a weekly basis.
Corresponding costs for academies are £243 plus £45 per week and for community schools, £210 plus £41 per week.
According to the figures, more than four out of ten (43%) parents with children of a school age drive them to or from school at least once a week, with the average number of journeys being four per week.
As a result, the average parent that drives spends an estimated £158.34 on fuel each year and clocks up an additional 889 miles.
However compared to 2012, there has been some respite for parents in that the amount spent on the school run has fallen slightly. Last year the average annual spend on fuel for the school run was £163 and the average number of miles travelled was 908.
On a per child basis, school uniform (£41.27), school shoes (£29.33) and jackets and coats (£25.22) are the biggest outlays for parents in advance of school term time.
And once the school term begins, the biggest regular outgoings (per child per week) are school trips (£8.97), packed lunches (£7.85), extra-curricular activities (£7.45), and school meals (£7.11).
“The end of the summer holidays means the annual back-to-school shopping trip for many parents. Unfortunately kitting out children for the new school term is an expensive task, which comes at a time when many families are under financial pressure and looking to rein in their spending,” said Alan Mathewson, chief executive of Santander Cards.
“There are ways to make the ‘back-to-school’ shopping spree a little easier and spending on a cashback card is a great example of how parents can earn while their children learn.”
Duncan Finch, executive managing director at Legal and General Insurance, added: “Few parents consider how much it costs to bring up a child and as Santander’s research shows, the money needed is continuing to rise. Often parents are surprised to find out how much this costs and we found that while on average new mums expect it to be £5,400 a year, in reality it is 59% more, amounting to £8,580 a year. The average amount needed to raise a child to the age of 18 is now £154,440; a 15% increase from 2011 and three times the amount of 2001*.
“Statistics like this, and Santander’s show how the fragile economy and increased living costs mean that it’s becoming more and more expensive to raise our children. Therefore it is vital that parents are fully aware of the potential costs so they can make sure they have an adequate financial plan in place for their family.
“Although unpalatable, it is also important for parents to plan for the worst by having a will and protection cover otherwise, your loved ones may not be left as financially secure as you would like.”
Recent weeks have seen major credit card providers step up their offerings, slashing balance transfer rates to 0% and extending the period this rate applies.