Parents will shell out £60 just on bottled water, during days out this summer.
The average family will take eight day trips, purchasing three bottles while out and about on each one.
And at a typical price of £2.50 a time, this soon adds up to the staggering sum.
The survey of 1,000 parents with kids aged 0-17 found 66 per cent reckon buying water at attractions is overpriced.
Terri Cooper from mineral water brand Aqua Pura, which commissioned the research, said: “Family days out are about having fun and making life-long memories, but the costs can easily add up.
“Having a car-boot filled with all those essential family trip items like suncream, extra snacks, spare clothes for the kids, games, a rug and a big pack of bottled water is a brilliant hack.
“It helps keep budgets down and avoid costly drinks runs.”
A fifth (22 per cent) of parents plan to take their children on more than 15 day trips this summer, which could cost more than £112.50 in extra bottles.
Parents blame a lack access to water fountains (39 per cent) for their reliance on buying water on the go, and a quarter (26 per cent) of parents distrust the water quality at refill stations when they do find them.
One in four (24 per cent) of parents find shared water fountains and refill stations unhygienic, and 12 per cent of children outright refuse to drink from them.
Terri Cooper from Aqua Pura added: “There are a number of hacks parents can deploy to avoid issues like this, and it definitely pays to buy ahead.
“My top tip to maximise family days out on a budget is to plan ahead – it doesn’t take long to fill your car boot with all those family essentials.
“Make your own budget-friendly snacks and stock up on £5 kids activity games that can be kept in the car, and the whole family can stay entertained and hydrated all summer.”
