New research from the charity data website shows that there are 78,764 registered charities dedicated to improving the lives of young people.
Given that there are 11.7 million people under 18 in England and Wales, the figures mean there is one charity for every 150 people under 18 in the two countries. For the 9.9 million elderly people, there are 39,354 charities - one for every 252.
All registered charities, including universities and housing associations, are included in the GuideStar figures, which come from Charity Commission data.
Les Hems, director of GuideStar UK, said children often featured as the preferred beneficiaries of many other charities as well. "If you have relief of poverty as your activity and you list the beneficiaries, children often appear on that list," he said.
Figures on the activities of charities put education on top at 72,299.
GuideStar estimates that about a quarter of these are either schools or school-related charities such as parent teacher associations, private school scholarship charities and school trusts. Culture and leisure is the second biggest activity, followed by 'economic wellbeing'.
A section on the types of charities show there are 36,313 service providers - 22 per cent of the 164,555 charities in England and Wales. The most common form is grantmakers, of which there are 55,669 - just over one in three.
A regional analysis shows that East Anglian charities derive the highest proportion of their annual income - 59.9 per cent - from the sale of goods and services, and the lowest - 22.6 per cent - from voluntary income.
In Wales, it is the other way round. Only a third of Welsh charities' income comes from sales, and they have the highest percentage - 46.6 per cent - of donated income.
The richest charitable region is London, with an income of £18bn - three times that of the next most prosperous area. The poorest region is the north east.
Hems said the data would help both the Government and the voluntary sector.
"We want to create indicators at national, regional and local authority level," he said. "If we are to support government policy and help voluntary bodies in local areas have a better understanding of their peers, we need a standardised set of measures."