SA economy better than expected: treasurer

South Australia's economy is worth more than $100 billion for the first time in the state's history, SA Treasurer Tom Koutsantonis says.

Data from the ABS shows SA's Gross State Product grew by 1.9 per cent in 2015-16 to reach $101.1 billion.

Mr Koutsantonis says the state's economy is performing "better than anyone expected", driven by more exports and growth in construction and mining.