The last time Qantas put a 747 into service was in 2003, so when the last one retires, it will be 17 years old.
"The jumbo has been the backbone of Qantas International for more than 40 years and we've flown nearly every type that Boeing built", Joyce said.
Qantas said it had ordered six additional Boeing Dreamliners for its worldwide fleet, that would enable the retirement of six 747s.
"The 787 has better economics and a longer range, and its already opened up new routes like Perth to London", Joyce said.
Uzbekistan Airways now operates two Dreamliners on worldwide routes, including Europe, Southeast Asia, Japan and USA. Qantas has options on 39 more Dreamliners as well 99 A320 NEOs, but with capital spending stalled over the last few years following 2014's $2.8 billion loss off the back of a $2.6 billion write down in the value of the global fleet, the planes have been showing their age and wear and tear. "It's fitting that its retirement is going to coincide with our centenary in 2020".
There are now 10 747-400 jumbos in the fleet, and these will be gradually scrapped between July and the end of 2020.
By contrast its 747-400s have 364 seats comprising 58 SkyBed seats in business, 36 seats premium economy and 270 in economy.
Is this the sweet spot for Qantas' Boeing 787 fleet?
It also expects to invest in an additional 787 simulator to train pilots.
The guidance was in line with the average estimate of A$1.55 billion of eight analysts polled by Thomson Reuters.
Qantas's market update said revenue across the airline group for the three months to March 31 2018 was $4.25 billion, up 7.5 per cent compared with the prior corresponding period.
Domestic revenue per passenger for the three months to March 31 increased eight per cent on the prior corresponding period - which Qantas says was partly due to the resources sector's continuing recovery - while worldwide revenue per passenger rose 5.2 per cent.
Mr Joyce added that the company was seeing robust results from each of its business units, which he attributed to "broadly positive" trading conditions.
"Their new 787-8 Dreamliner will continue to contribute to the airline's success with its superior passenger experience and comfort, exceptional efficiency and low operating costs", said Marty Bentrott, VP, Sales, Boeing Commercial Airplanes, for Middle East, Turkey, Russia, Central Asia and Africa.
"A large part of our earnings momentum is driven by ongoing investment in customer experience". Interiors of the 787s will feature the same configuration as existing aircrafts.
"We've also continued to broaden our earning streams with health insurance and financial services under Qantas Loyalty".