Grandparents who help out their children are saving them an average £3,500 a year in childcare costs and other family expenses, according to a recent survey.
Many generous retirees also regularly pay out to supplement their children's incomes and boost their grandchildren's living standards.
The study, by over-50s insurer RIAS, found the amount of time grandparents spent on free childcare went up from nine hours a week to ten over the past year.
Researchers calculated that 5.8million grandparents – 47% of all – are providing free childcare which would cost around £35 a week if paid to a childminder.
The 21st Century Grandparenting report, based on a survey carried out by Opinium among 2,135 grandparents, found that 49% also give cash help to their children's families.
The findings revealed that grandparents spend an average £108 a year for their grandchildren's clothes, £101 for recreation and days out, £424 in gifts and £369 towards special items such as laptops or driving lessons. In total, they subsidise their families to the tune of £1,701 a year, it found.
More than a quarter of grandparents say their childcare contributions have 'significantly' increased over the past year. Similar numbers say the rise is because mothers have gone back to work, parents are working longer hours, or professional childcare costs have risen.
Sarah Howe from RIAS said: "With the cost of childcare rising by almost 5% this year, in line with inflation at 5.2%, grandparents have continued to step in to support working parents.
"The knock-on effects of parents having to return to work, working longer hours, and rising childcare costs mean that grandparents are providing a fundamental and crucial benefit to families – a trend that we've seen over the last few years."