Deputy CEO Pongsakti Semsan said the construction of a new 155 million baht terminal for group and charter passengers as well as the new international terminal would allow the growth.
He also said that AoT expected to make two billion baht profit on revenue of four billion baht in the full calendar year 2013.
A large group of senior executives came from Bangkok yesterday to lay the foundation stone for Terminal X, which will mostly handle charters and groups.
It's expected to open around the same time or a little before the new international terminal in May, 2015.
Projecting the figure of 20 million, up from the previous 12.5 million, explains where AoT will find the capacity to handle Phuket's extraordinary growth in tourist numbers.
In line with Phuketwan's estimates, the AoT believes arrivals and departures through the Phuket facility could reach 11 million this year.
''Flights are coming at the rate of 200 a day and 30,000 passengers are passing through the airport,'' Khun Pongsakti said.
''From the end of October we expect that figure will rise to 215-220 flights a day for the high season. The number of passengers continues to grow day by day.''
Larger aircraft will be required to boost the passenger numbers to 20 million because Phuket still has only one runway.
A strategy for the improved infrastructure necessary to handle 10 million arriving passengers once they leave the airport has yet to be spelled out by Phuket authorities.
The island is already struggling to retain its natural appeal - the west coast's beaches and coral reefs - with a figure of half what AoT is now saying could be achieved in 2016-17.
The word ''sustainability'' was not heard at Phuket International Airport yesterday. Figures for passengers and profit took precedence.
The airport remains Phuket's most important piece of infrastructure, and that applies to the neighboring provinces of Phang Nga and Krabi as well.
While Phuket's authorities have been talking up plans to reform the chaotic taxi and tuk-tuk system and save Phuket's beaches from exploitation, little has actually been achieved so far.
With the private AoT creaming two billion baht in profit and charging taxi groups high rents that boost taxi fares to extortionate levels, the pockets of Phuket tourists and travellers appeared to be viewed as extremely deep, perhaps even bottomless.
The number of passengers rose year on year in the financial year to October 1 by an amazing 33.7 percent. Flights tallied 71,198, up 27.38 percent.
In September alone, 833,001 passengers arrived and departed from Phuket airport, up 31.41 percent on September 2012.
International travellers rose 38.61 percent while domestics numbers were up by 23.86 percent.
The January-September total reached 8.4 million, with October November and December to come.
If the Chinese market falls away slightly as predicted because of new laws governing travel from China from October 1, the likelihood is that Phuket airport could fall a fraction short of the 11 million total for 2013.