Two million women are estimated to be victims of violence perpetrated by men each year in an epidemic so serious it amounts to a “national emergency”, police chiefs have warned.

Crimes including stalking, harassment, sexual assault and domestic violence affect one in 12 women in England and Wales, with the number of recorded offences growing by 37% in the past five years and the perpetrators getting younger.

The figures are contained in the first national analysis of the scale of violence against women and girls (VAWG) by the National Police Chiefs’ Council (NPCC), released on Tuesday.

Police chiefs also warned of young men being “radicalised” online by influencers such as Andrew Tate. They demanded technology companies act more quickly to take down extreme material.

The report says: “We estimate that at least one in every 12 women will be a victim of VAWG every year (2 million victims) and one in 20 adults in England and Wales will be a perpetrator of VAWG every year (2.3 million perpetrators). These are cautious estimates as we know much crime goes unreported and in policing we often only see the tip of the iceberg.”

This year, amid growing horror over the scale of offending, the Guardian launched Killed Women Count, a project reporting on every woman allegedly killed by a man throughout 2024, whose stories often go untold.

Keir Starmer, the new prime minister, has promised to halve violence against women and girls within a decade, with taskforces in each police force including specialist domestic abuse workers responding to 999 calls.

The NPCC report, which analysed official data, said:

• 20% of all police-recorded crimes – more than 1m offences a year – count as VAWG. These include sexual assault, stalking, harassment, domestic violence, and controlling and coercive behaviour. The true total is estimated in the report to be twice as high.

• Child sexual abuse and exploitation increased by more than 400% between 2013 and 2022. Offences committed by children increased to 55.6% of the total. The average age of victims is 13, with suspects averaging 15 years old.

Maggie Blyth, the police national lead for VAWG, said: “Violence against women and girls is a national emergency. We need the support and direction of government to intervene and address the current problems within the criminal justice system and lead the way on a whole-system approach to VAWG.

“We need to move forward as a society to make change and no longer accept VAWG as inevitable.”

Louisa Rolfe, the national lead for domestic abuse and an assistant commissioner in the Metropolitan police, said the real figure for victims was probably even higher as many offences were not reported. “I think it is more, more like 4 million,” she said.

Part of the increase was being driven by extreme material on the internet, police said. Rolfe said there had been an increase in non-fatal strangulation among younger people, with men believing it was part of a normal sexual relationship, without women’s consent, which she described as “really frightening”.

She added: “All the academic research will tell you that the difference between non-fatal strangulation and fatal strangulation is millibars of pressure.”

Blyth said the police counter-terrorism command and those tackling VAWG were discussing the influence of influencers and how to counter it. “We know that some of this is also linked to radicalisation of young people online … we know the influencers, Andrew Tate. The element of influencing, of particularly boys, is quite terrifying,” she said.

“Misogyny is inherent in some of the ways of working that are behind these crime types, behind boys growing up and their use of violence. This is why the online threat is so significant for us.”

Other data shows the fastest-growing groups of domestic abuse offenders and victims of domestic abuse are those aged 16 to 19.

Police privately say delays in bringing domestic abuse prosecutions mean most victims withdraw support for a prosecution after seven days.

Blyth said the justice system was a problem: “We don’t think it is functioning … We know that we’ve got significant delays within the court system. We know that victims are waiting far too long for a criminal justice outcome. And we know that some victims fall away through that process.”

Focus on VAWG intensified after the 2021 rape and murder of Sarah Everard by a serving Met officer, Wayne Couzens, who had previously been investigated for indecent exposure. An official report found wide-scale failings and the second part of the inquiry, expected next year, is also set to be damning.

Police now say VAWG should be treated as seriously as terrorism. They are setting up a national centre to improve results, with 43 forces across Britain having a multitude of approaches. They promise better training and say reforms are already bringing more offenders to justice.

Harriet Wistrich of the Centre for Women’s Justice said: “The [NPCC] report makes little mention of the issue of police perpetrators of VAWG, which – following the recent exposure of the scale and nature of this issue – has massively dented trust in the police from victims.

“It also does not tackle head-on the issue of criminalisation of survivors of violence which, aside from being an affront to justice, is a huge waste of criminal justice resources.”

Clare Kelly, the associate head of policy at the NSPCC, said: “Tech companies must … step up to stop boys from being targeted with vile misogynistic content and put safety measures in place to prevent grooming and sexual abuse proliferating their platforms.

“Schools also need support to deliver effective relationships and sex education that is high-quality, inclusive and relevant to the realities of children’s lives to embed a culture where girls are safe, heard and empowered and healthy relationships thrive.”

The safeguarding minister, Jess Phillips, said: “The scale of violence against women and girls in our country is intolerable and this government will treat it as the national emergency that it is.”