The cost of raising a child and supporting them through university has risen by £5,000 over the past 12 months to £227,266, according to figures put together by the Centre of Economic and Business Research (CEBR).

The research, commissioned by the insurer LV=, looked at expenses over the first 21 years of someone's life, from food and clothing to hobbies and education.

Parents now spend an average of 28% of their household income on their children, with the biggest chunk – £73,803 – going on education, followed by childcare, which adds up to £66,113.

A survey of parents carried out alongside the research found that rising costs and changes to family benefits meant one in five were putting off having another child, while 71% said they had been forced to make cut backs.

The latest annual Cost of a Child report looked at how prices had changed since the report's first edition in 2003. Over that period the total cost rose by 62%, while the cost of a child's first year increased by 50% to £11,025.

The full facts: cost of raising a child 2003-2014

*Does not include private school fees, but does include associated day-to-day costs (eg school trips, text books, uniform and school lunch) and university fees. Table: LV=

Some parents with children under the age of one have been hit by changes to the child benefit rules introduced in January 2013, which mean that households where a parent earns more than £50,000 must repay a proportion of the benefit through a tax charge. Once a parent is earning £60,000 the whole benefit is clawed back.

It is education costs that have jumped the most since 2003, with university fees driving the total up by more than 123%.

The education total also takes into account fees for school trips, uniforms and other spending associated with a state school. The CEBR said parents who opted to send their child to a private school would pay an extra £117,357 on average for a day school, or £215,853 for a boarding school.

Childcare and babysitting costs showed the biggest annual rise, and are up by 3.7% since the last report. The Daycare Trust has put the average cost of childcare at £405 a month, and LV= found that mums believed they now needed to earn an average of more than £26,000 a year to make it worth returning to work.

The need to make family finances go further meant parents had cut the amount they put aside for the future. One in three said they had reduced the amount they saved and one in 10 had cancelled or reviewed spending on insurance.

The survey showed that single parents were being hardest hit by rising costs, now spending 54% of their pay on their children.

Lone parent charity Gingerbread said its own research had shown how many families were struggling.

Its chief executive, Fiona Weir, said: "Three-quarters of single parents surveyed by Gingerbread feel worse off than they did a year ago, and almost two-thirds say they expect their financial situation to worsen over the next year.

"Single parents are doing a remarkable job holding their families together while under immense financial pressure – but it's taking its toll. Many have pared back all they can and now face debt and very difficult decisions over heating and food for their families."

Figures from the Office for National Statistics published on Tuesday suggest that for many parents the costs do not stop when a child turns 21, as a record number of young adults are living in the family home.