Boeing expects 59% of the 35,280 aircraft deliveries over the next 20 years to be directed at the growth market.
It disclosed the figures in its latest commercial market outlook covering the period to 2032.
The other 14,350 deliveries will be used for replacement.
Some 5,960 current aircraft will be retained, raising the overall global fleet in 2032 to 41,240 - effectively doubling the 2012 population of 20,310.
Boeing says 70% of this expanded global fleet will comprise single-aisle types such as the 737 and the Airbus A320, an increase on the current 64%.
Vice-president for marketing Randy Tinseth says this forecast probably leaves room for a third competitor, even given the high production rates of 737s and A320s.
It predicts that the proportion of high-capacity types will halve to 2% while the regional jet market will shrink from 13% to just 5%.
Small and medium-size twin-aisle aircraft will account for 22% of the fleet, up from 19%.