Up to a quarter of children in England and Wales have been victims of crime, according to Home Office analysis.
The experimental British Crime Survey figures said up to 2.2m crimes of theft and violence took place against under 16s.
Statisticians said the figures were just one of four ways of counting incidents - including playground spats.
When asked to judge for themselves, just 6% of children perceived themselves to be victims of crime.
It is the first full attempt in the UK to work out how many children aged between 10 and 15 experience crime.
The experimental figures for the Home Office have been almost two years in the making. The former Labour government launched the project amid pressure to work out how many under-16s were victims of crime.
The pilot project interviewed 3,700 children in their homes in 2009 as part of the rolling British Crime Survey (BCS), the government's favoured measure of counting crime. The researchers came up with four measures for counting children's experiences during the previous 12 months.
One of these methods counted every possible act of wrongdoing that could be potentially recorded by the police, including:
- A child deliberately smashing a toy belonging to their sibling
- Dinner money being "stolen" but later returned
- A playground fight resulting in a nosebleed
Two of the other measures used by the researchers screened out childish behaviour and minor school incidents that would neither overly worry carers nor concern the police. The final measure counted the child's own subjective perceptions of a crime.
The first category, all possible incidents that would be hypothetically recordable by police, suggested that 24% of all children were a victim of theft and violence - a rate four times higher than for adults. But each of the other three categories saw the numbers progressively drop.
The measure producing the lowest levels of crime was that based on the child's own perception of whether they had been a victim. That method suggested there were 404,000 crimes, rather than 2.2m, even though some of the children counted trivial incidents, such as another child stealing a favourite, although inexpensive, toy.
Across all categories, the experimental data showed that children were far less likely to report their experiences than adults with just 11% going to the police compared to almost four in 10 adults.
The study focused on theft and violence and did not include sexual abuse, cyber bullying or other crimes that would be captured in the main BCS interview of adults.
John Flatley, the report's editor, said there needed to be a public debate about which of the measures, if any, should be used. His team came across difficult contradictions between what could be classed as a crime, what society would dismiss as childishness behaviour - and what a child thought about the event.
"This research fills an important gap in the evidence base that we did not have before," he said. "It quantifies what we suspected, but we did not have the numbers to show it. We expected that children would have higher levels of victimisation than adults and that most of it would be dominated by low level violence and that the serious stuff is relatively rare."
The Home Office is asking the public about the experiment in a consultation which runs until September (see internet links).
Police Minister Nick Herbert said: "These new figures reinforce our longstanding belief that, to date, crime measures have offered either a partial or confused picture about the level of offending.
"We need a commonsense approach that recognises young people's experiences so that we don't criminalise children by failing to properly distinguish between playground spats and serious crime."