National Literacy Trust highlights book-free millions
Almost four million children in the UK do not own a book, according to a report by the National Literacy Trust.
The proportion of children without books is increasing, the charity said. It is now one in three, compared with one in 10 in 2005.
Children with their own books were more likely to be above-average readers and do better at school, the study of 18,000 children suggested.
Poorer children and boys were less likely to have books, it added.
The survey was carried out in September with school-aged children from 111 schools across the UK.
It suggested that a third (33.2%) did not have books of their own. That translates to 3.8m children UK-wide.
Better off children and young people were more likely to say they had books of their own, compared with those who received free school meals.
Trust director Jonathan Douglas said the steep rise in the number of children without their own books was of particular concern.
He said: "We know there is a direct correlation between book ownership and children's reading abilities.
"With one in 6 in the UK struggling with literacy it is very worrying that many children could be missing out on opportunities to develop these essential skills."
The trust said that children who owned books were more likely than others to read every day, and that book ownership had a clear link with reading ability.
Of the children and young people with books of their own, more than half read above the level expected for their age, with fewer than one in 10 reading below the level.
By contrast, among those without books of their own, nearly a fifth were failing to meet the expected reading level, with only a third reading above that level.
The trust launched the survey to coincide with an appeal for public donations towards books and reading support for disadvantaged children.
A number of children's book illustrators have designed cards to support the trust's Christmas Gift of Reading campaign.
The survey also revealed links between reading ability and receiving books as presents.
About a fifth of children said they had never been to a book shop or a library.
But the survey also showed that reading any type of material, for example magazines, outside class at least once a month was also associated with greater reading attainment.