The final quarterly economic report published by the UK government's Department for Culture Media and Sport said the overall cost of delivering the Games was £8.92 billion, lower than the £9.3bn set aside.
That works out at £142 per head for every man, woman and child in the United Kingdom.
The London 2012 Organising Committee's own £2.2bn operational budget for the day-to-day running of the Games came almost entirely from sponsorship, ticket sales, merchandise and from the International Olympic Committee.
However, the actual "Games-time" cost ran close to £3bn when adding on £514m for venue security and £137m for "operational provisions" as well as extra money for more lavish ceremonies, all of which came from the public purse.
A DCMS spokesman said the government had always been committed to providing LOCOG funds for venue security, initially estimated at £282m.
The final figure for Games-time security does not take into account any savings resulting from the security firm G4S's failure to deliver its Olympic contract in full.
Despite steep rises in venue security costs as the Games approached, the figures released on Tuesday showed £480m in unused contingency from the public funding package.
While the operational costs escalated, the report said the Olympic Delivery Authority, the government-funded body responsible for building the venues and infrastructure, completed the project for £6.71bn, £1bn less than initially forecast.
The ODA budget was reduced by £47m between May and September, despite a £36 million increase in completing the athletes' village, much of the savings coming from reduced transport costs.
"We are pleased to report even more savings made through careful stewardship of public money," ODA chief executive Dennis Hone said.
"We are now entering the final phase of the ODA's work, transforming the Olympic Village into thousands of new homes and building a community that will become established, grow and mature in the decades ahead - a London 2012 legacy for generations to come."
The final budget report came on the day LOCOG began handing back parts of the Olympic Park to the London Legacy Development Corporation, who will transform the sprawling east London site into the Queen Elizabeth Olympic Park.
"We have now begun the first chapter of the lasting legacy we promised when we bid for the Games," LOCOG chairman Sebastian Coe said in a statement.
The £292m project will remove temporary venues, complete a retro-fit of the Olympic Village to create a new London community with 2,800 homes and install new roads and pathways.
A phased re-opening of the Olympic Park is expected to begin in July 2013.
- Sports & Recreation
- Politics & Government