WA parents are shelling out an average of almost $240 a week to raise their teenagers, with 17-year-olds found to be the most expensive.
Suncorp Bank's Cost of Kids report found teenagers put a big financial burden on their parents, costing them more than 15 per cent of the State's average weekly wage.
When taking into account food, clothes, health, mobile phones and computers, extra-curricular activities and transport, the bills keep on stacking up for parents.
But by the time the children hit 17, additional tuition, driving lessons, car registration and insurance and high school formals really start to bite.
The report also found that while costly, infants do not hit their parents' hip pockets as hard as older children, costing them $206 a week, mostly because of big financial outlays such as for baby furniture, car seats and medical expenses.
Toddlers and primary schoolers were the cheapest ages, taking $167 and $163 a week each out of the budget.
The cost of raising a teenager is more than $12,000 a year, but it skyrockets for parents who opt for a private education over the public system, Suncorp Bank WA general manager Carl Cockerham said, with the average weekly cost of education rising from $18 to $393.
Sonia Michl, whose son Anthony Foley is 17 and about to start work as an apprentice electrician, agreed raising teenagers did not come cheap.
Ms Michl said she helped Anthony financially by lending him her car, paying for petrol and insurance and subsidising his sport as well as all the basic necessities.
"When it's during school holidays they can cost a lot more because you are trying to keep them occupied and sports registration and kits are really expensive," she said.
Anthony said his parents were "pretty good" to him and paid his phone bill because he was not yet earning. When he does start work, however, he will save for a car and his parents will help by matching his savings dollar for dollar.
"I think it is important to show them the value of money and we've done that a lot," Ms Michl said.
Food was the biggest single weekly expense when raising children; it was cheapest for toddlers at $38 a week and most expensive for teenagers, adding $75 to the grocery bill.