In the first half of 2015, smartphone users in both the countries were most likely to be interested in a device with a display size of 5.3-inch overall, according to the report.
The findings also showed that respondents surveyed in the US have a greater interest in the larger sized prototypes than those surveyed in the UK, while Android owners have a greater interest in phablet sized prototypes compared to Apple owners.
Current smartphone owners are also more likely to prefer a thicker prototype with a longer battery life over a thinner phone, researchers said.
Even though the majority of smartphone owners surveyed preferred a prototype with a display larger than their current device, more than half of respondents expressed interest in a device that was only slightly larger than their current display size.
"While interest in larger displays is considerable for current consumers it is still imperative to keep in mind that a device with good 'fit in hand' is important," said Monica Wong, analyst and author of the report from the Mobile Device UX (MDX) group at Strategy Analytics.
