The Internet and the "digitally enabled economy" are forecast to contribute $139 billion to gross domestic product within half a decade. 

A new report produced by Deloitte on behalf of Google claims that digital technologies including the Internet are currently contributing $78.8 billion to Australia's economy — 5.1 per cent of GDP — including $51.7 billion in the private sector outside of ICT and media and $14.1 billion in education, health and government.

"It's getting harder and harder to separate the digital economy from the rest of our economy which can only be a positive, because it means technology is being embraced everywhere from healthcare to education, from agriculture to the delivery of government services," Google Australia and New Zealand managing director, Maile Carnegie, said in a statement.

"When we first calculated the value of the internet economy in 2011, we all knew it was growing rapidly, but just as technology and levels of connectivity have evolved, so has the value of digital to the Australian economy," Deloitte Access Economics partner Ric Simes said.

"The challenge now is to ensure that we don't take our foot off the accelerator because the health of the digital economy will be critical to Australia's future prosperity," said Simes, who was a co-author of the report.

The report states that although the ICT sector has slightly declined across OECD economies in recent year, "digital technologies are clearly playing a more important role in our economy, and most of this is captured by the impact of digital technologies on sectors outside of ICT."

"In general, we have seen the internet become more integrated within existing businesses," the report states.

"It is becoming harder to distinguish a 'digital economy' from the broader economy. It is harder to measure the digital economy."