With smaller, seven-inch tablets dropping in price rapidly and expensive high-end smartphone sizes creeping up past six inches it seems that one market or the other will be enveloped in the other at some point.

Today a new DigiTimes report signals that growing smartphones may have reached their upper size-limit. The report cites unnamed “industry sources” as stating sales of smartphones with displays over 6 inches have been disappointing for manufacturers. Consumers should expect the largest smartphones in the near future to top out somewhere in the five- to six-inch range.

The report’s sources singled out Samsung’s Galaxy Mega and Sony’s Xperia Z Ultra as two of the mega-sized phones that have not met manufacturer sales expectations. The Galaxy Mega houses much of the same hardware as the Galaxy S4, but with a 6.3-inch screen. The Xperia Z Ultra tops even the Galaxy Mega’s screen sized with a massive 6.4-inch display.

DigiTimes reported that smartphones with displays between five and seven inches mad up only 20% of smartphone sales during the third quarter of 2013. However, phones on the larger six- to seven-inch range of this segment contributed only 3% to those sales.

The reasons for the disappointing sales of so-called “phablets” aren’t hard to understand. While smartphones are still meant to be portable, devices with displays over six inches are more difficult to transport and often don’t fit into normal-sized pockets. Also, as the largest smartphones are still priced at premium-smartphone levels, the value proposition between an expensive 6-inch smartphone and a sub-$200 tablet is clearly on the size of tablets, which often have the same features consumers are looking for in larger smartphones.

(Image courtesy HTC)