Mr Frydenberg's first budget update has also exposed a $11 billion war chest at the government's disposal ahead of the next election, which could mean extra money in Australian's pockets.

But Labor has accused the Liberal-National coalition of benefiting from good global conditions without doing the hard yards.

The mid-year budget outlook, published on Monday, shows the government is on track for $4.1 billion surplus in 2019/20, almost double the $2.2 billion figure it had forecast in May.

Beyond that, the coalition expects to deliver surpluses for the next decade, including $12.5 billion in 2020/21 and $19 billion in 2021/22.

The government has also cut its deficit forecast for this financial year to $5.2 billion, from the $14.5 billion it had projected in May.

The improvements come after the government raked in more revenue than expected, buoyed by strong employment growth and corporate tax receipts.

The other side of the ledger has also helped, with the government making fewer payments.

Mr Frydenberg said the result was "no accident", pinning it instead on sound economic management.

But he said the nation's books being in good shape is not an end in itself.

"It is a means for a better way of life for more Australians," he told reporters in Canberra on Monday.

Labor says a rosy global picture has led to the better results.

"This is a government which is riding on the back of a good international economy and has given up on the task of budget repair themselves," shadow treasurer Chris Bowen said.

"Growth is down, investment growth is down, wages growth is down, consumption growth is down, and the only thing that's up is terms of trade."

Growth is forecast in the statement to be 2.75 per cent this financial year, before speeding up to three per cent in 2019/20 and staying at that pace for the following two years.

The unemployment rate is projected to remain at five per cent this year, and remain that way up until mid-2022.

But the government has trimmed its wage growth forecasts by 0.25 per cent for this financial year and the next, with 2.5 per cent wage expected for 2018/19 and three per cent in 2019/20.

The opposition drew attention to Australia's debt levels, with net debt forecast to hit $351.9 billion in 2018-19.

But Mr Frydenberg said that was expected to be whittled down, hitting $48.4 billion - or 1.5 per cent of gross domestic product - in 2028/29.

The statement also outlines the costs associated with policies introduced since the budget in May, including an extra $3.2 billion over 10 years for non-government schools.

A multi-billion-dollar "contingency reserve" could allow for spending, such as deeper tax cuts, aimed at impressing voters.

Australian Associated Press