Apple has announced more than 85 million users for iCloud.

Apple had launched its iCloud service 3 months ago. But it has not more than 85 million users since tha launch. This was announced by Peter Oppenheimer, Apple’s Senior Vice President and Chief Financial Office, on today’s Q1 2012 financial earning calls.

During that time frame, 64 million iOS devices were sold! In fact, that’s also more users Dropbox reported in in late in 2011.

This seems an impressive growth rate by iCloud. iCloud allows iOS and Mac users to sync select file types across devices. It replaced the company’s previous subscription service called MobileMe with a more rich feature set. Also, unlike MobileMe, iCloud is a free service — which should mostly explain the explosive growth.