This was to incorporate new sectors in the economy.
The east African country's GDP stood at 68.4 trillion Ugandan shillings (24.69 billion US dollars) at the end of the 2013/14 financial year, after the rebasing, the finance ministry said on Friday, from a previous estimate of 60.5 trillion shillings.
The ministry said it changed the base year for its GDP calculations to 2009/10 from 2002.
Uganda follows in the footsteps of other sub-Saharan African countries including Nigeria and Kenya which have rebased their economies to try to capture the output of new sectors like information technology and entertainment services.
(READ MORE: Ugandan economy pressured by investment challenges)
Uganda's rebasing exercise means debt levels fall as a proportion of GDP, a closely watched ratio, and could give the government some leeway for more borrowing to help finance its plans to build new transport links and repair creaking infrastructure.
At a function to release results of the rebasing, Finance Minister Maria Kiwanuka said the government now had a better understanding of "sectors where investments should be channelled in order to grow the economy and create jobs."
With a population of about 34.9 million people, Uganda's GDP per capita now stands at about 700 US dollars.
Uganda expects to start pumping crude oil in 2018 after commercial reserves, estimated at 6.5 billion barrels, was found in 2006.