The figures were published by HMIC to analyse forces in England and Wales
Police officers and staff in England and Wales spend just under a third of the time to investigating crime and preparing cases, figures suggest.
Forces devote about a fifth of their work to "support functions" like training, accounting and planning, says HM Inspectorate of Constabulary (HMIC).
About 47% of the time is taken up by community-related tasks, policing roads and answering phone calls.
HMIC said the "value-for-money" data can conceal variations among forces.
The figures were published by the inspectorate as part of a new website - hmic.gov.uk - which analyses the work of all 43 police forces across England and Wales.
HMIC "report cards" issued earlier in the month highlighted the performance of each force.
According to the figures, 31% of police time is devoted to "dealing with criminals" - tasks such as investigating offences, gathering intelligence, processing forensic evidence and preparing cases for court.
There are about 143,800 full-time police officers, 16,500 civilian community support officers and 82,190 support staff.
HMIC said the cost of meeting wages accounts for more than 80% of the annual £13.5bn policing bill.
Denis O'Connor, Chief Inspector of Constabulary, said the findings provide transparency about police work.
He said: "The public want to know where all the police are. Today we have gone some way to answering this with our value-for-money profiles. They show what the police are working on nationally and locally."
However, he added that "better information alone does not tell the public the whole story".
"The police need to be asked why their costs vary from force to force. Police authorities need to be using comparative information to challenge constructively," he said.
Policing and Crime Minister David Hanson MP said crime was falling and "confidence in the police is going up". But he added that "people have the right to know we are getting full value for the historically high levels of funding in the service".
He said the government's White Paper "laid down a challenge to chief constables and police authorities to save at least £545m a year by 2014 so even more money can be spent where the public wants it - on the frontline".
"By continuing to cut bureaucracy, using better procurement and introducing smarter working practices, the police can ensure they provide even better value for money and the HMIC inspections will show their progress," said the minister.
But shadow home secretary Chris Grayling said the figures showed "how utterly out of touch Labour policy is".
"We'll never begin the fight back against crime until we slash the paperwork that's keeping officers off our streets and behind their desks. Gordon Brown and his team just don't get it," he said.