Chief executive Sam Laidlaw said its contribution to GDP was equivalent to a city the size of Manchester, and its tax bill amounted to £158 for every UK household.
Centrica has published the findings of its specially commissioned report in a week when it faces a backlash over an expected double-digit rise in profits, after increasing bills by 6% for around 8.5 million households at the end of last year.
Consumer Focus called for greater transparency between profits and prices earlier this month after rival utility giant EDF revealed a £1.7 billion earnings haul just two months after raising bills for 3.7 million British households.
But Mr Laidlaw said the study showed how companies like Centrica were an engine for sustaining and stimulating growth. He said: "At a time of uncertain economic prospects, our activities across the UK are even more important to secure employment, put the supply chain to work and contribute our fair share of tax."
Centrica is also keen to highlight its contribution to Government coffers and said the company and its staff paid £1.1 billion in tax last year.
Oxford Economics chief executive Adrian Cooper said: "By generating tax revenue, supporting jobs and stimulating economic activity along its supply chain, the impact of Centrica's activities is shown to extend well beyond its core function of delivering a secure energy supply to businesses and consumers across the country."
The researchers also said that for every £1 billion Centrica contributes to GDP itself, it generates another £2.9 billion in the rest of the UK economy through multiplier impacts.
Oxford Economics has also carried out research for other blue-chip companies, including Sky and Rolls-Royce.