IDC now expects 117.1 million tablets to ship in 2012 (up from the previous estimate of 107.4 million), with this rising to 165.9 million in 2013 (up from 142.8 million) and 261.4 million in 2016.
The researcher expects iOS to maintain its market dominance over the next four years, reaching a 60% share this year before dipping to 58% by 2016, a figure which would essentially put Apple as shipping just over 150 million iPads a year.
Apple claims to have sold 84 million iPads since March 2010.
Despite the good news for iOS, IDC sees difficulties ahead for Android and Windows. The firm expects Android market share to drop from 38.9% in 2011 to 30.5% by 2016, and forecasts Windows (including Windows 7 and RT models) to grow from 4% in 2012 to just 11% by 2016.
"Apple leads the market with its iPad, and we expect its dominance to continue in the second half of the year," said Tom Mainelli, research director of Mobile Connected Devices at IDC.
"Still, we believe there is room in the market for others to find success, and new Android- and Windows-based products shipping in the coming months will give consumers plenty of buying options during the holiday season."
IDC research analyst Jennifer Song agrees that Windows 8 has potential, but reiterates previous concerns from IDC that too many tablets could cause customer confusion.
"We expect shipments to remain low in the fourth quarter as high prices and consumer confusion around these devices will limit their appeal," said Song.