The fall of around three days compared with previous years is attributed to the destination becoming more affordable, the agency claimed in its first Australia Travel Trends report.
In it, Flight Centre data revealed business class rates to Australia were an average 10% cheaper in 2016 compared with the previous year, with premium economy rates as much as 34% less than in 2015.
Rates have fallen as the number of flight options has grown, with Gulf airlines especially having targeted the Kangaroo Route from their Middle East hubs.
Flight Centre estimates capacity to Melbourne in the 2012-2016 timespan grew 31%, Sydney by 24% and Adelaide by 18%, while Brisbane was up 11%.
In percentage terms, the biggest growth in the four-year period however was to the Gold Coast (up 1,140%) and Cairns, gateway to the Barrier Reef, up 300%.
Only Perth remained static, but the Western Australian city’s popularity is predicted to increase next year when Qantas begins its non-stop 17-hour flight from Heathrow using the Boeing 787 Dreamliner.
The agency is predicting that 2017 will see airlines reduce fares further as the weakening pound affects demand. Flight Centre now sells more than 1.3 million tickets to Australia per year, with 30% of passengers taking an internal flight.