With Apple Inc expected to launch an iWatch later this year based on various reports, analysts have begun to speculate and make their own predictions as to how many wearable devices the iPhone maker can sell.

According to market watchers, Apple's rumoured iWatch will sell to at least 10 per cent of iPhone users during the device's first full year in the market. With an estimated iPhone user base of 335 million by the end of 2014, BMO Capital Markets analyst Keith Bachman said Apple may be able to sell 33.5 million of the iWatch in 2015. In a note to investors obtained by Apple Insider, the figure is only Bachman's low-end prediction for potential iWatch sales.

If Apple Inc can attract at least 15 per cent of existing iPhone users, iWatch sales may increase to 50.3 million units. If 20 per cent of iPhone owners were to buy the wrist-worn device, the company may sell about 67 million iWatches in 2015.

The report said the analyst based his figures on the device's average selling price of $250 per unit with a gross margin of about 25 per cent. Bachman predicts a 10 per cent market penetration for the iWatch on iPhone owners would increase Apple's earnings per share by 3.1 per cent for the calendar year 2015. He said a 20 per cent adoption rate would increase the company's EPS by 6.2 per cent.

Bachman's note suggested that the key driver for consumers to buy the iWatch is "meaningful applications." Health and fitness applications may not be enough to reach a 20 per cent adoption. Apple Inc should be able to include work or professional applications to achieve higher adoption.

BMO Capital Markets continues to maintain an "outperform" rating for Apple's stock with a price target of $98. Its new price target already reflects Apple's 7-for-one stock split last week.

Rumours of Apple releasing an iWatch have become persistent and multiplied in number that many analysts seem to think it is inevitable. Other reports said Apple's wearable device may be released in October to make it available for holiday shoppers in December.