Daughters are more costly to raise than sons, according to a survey of British parents.
From birth until the age of five, girls are around STG300 ($A523.74) more expensive a year than boys, Sainsbury's Bank found.
The cost gap doubles during the teenage years, with parents of girls aged between 14 and 18 typically forking out nearly STG600 a year more than parents of boys of the same age.
The research suggested the gap may in part be due to girls' clothing being more expensive than that for boys.
The survey also showed that parents of children under the age of 25 estimated that, on average, 21 per cent of their monthly household income is spent directly on items for their children.
And the average parent expects to be supporting their child financially well into their adulthood - until the age of 29.
Jasmine Birtles, founder of website MoneyMagpie.com, wrote a report on the findings.
She said: "I'm surprised that parents feel that even when small, their daughters cost more than their sons. Are parents buying more outfits for their tiny girls?"
More than 2000 people from across the UK took part in the survey and parents were asked to estimate the annual cost of raising their children.
The research found that up to the age of five, the average annual cost of raising a girl is STG5767, while a boy is typically STG292 a year cheaper, costing parents STG5475.
Between the ages of six and 13, a girl costs parents STG6794 a year, while a boy costs STG6414.
Between the ages of 14 and 18, a girl costs parents STG7747, while a son costs STG7172, according to the report.
Andrew Hagger, founder of Moneycomms.co.uk, who also contributed to the report, said: "Whether it's a boy or a girl, household finances can be turned on their head when the first child is born - a sudden spike in expenditure and potentially less income means that the family purse needs to be managed more closely."
But many parents said the cost burden was less severe for subsequent children.
Three-quarters of parents with more than one child said first-born children were more expensive to raise than their siblings.
Many parents had kept the costs of younger children down by reusing items such as toys and clothing.