Apple Inc's Watch has the lowest ratio of hardware costs to retail price across any Apple phone, according to a preliminary estimate by research firm IHS after a teardown study.

The hardware cost of an Apple Watch Sport model was about 24 percent of the suggested retail price compared with 29-38 percent for the iPhone maker's other products, IHS said on Thursday. (bit.ly/1zuOZMq)

The Apple Watch Sport 38 mm costs $349 and the teardown shows a bill of materials of $81.20 with the cost of production rising to $83.70 when $2.50 in manufacturing expense is added, IHS said.