Has Apple sold its 500 millionth iPhone?

It appears that Apple may have recently sold its 500 millionth iPhone. News of the milestone, which will likely be touted by Apple during their next earnings report in April, was first noticed by Forbes earlier this week.

Here's how the data all comes together.

At the beginning of Apple's most recent quarter, the company had already sold 472 million iPhones. Using Apple's Q2 of 2013 as a barometer, we find that Apple during the March 2013 quarter sold 37.4 million iPhones. That's about 415,555.55 iPhones sold every single day. To get to 500 million, Apple needed 28 million in iPhone sales beginning in January.

Employing some basic arithmetic (28 million/415,555), and assuming that the iPhone sell through rate remains constant throughout the quarter, we see that Apple would need just 67.37 days to reach the 500 million iPhone mark. That would mean that the milestone likely occurred on or around March 7.

So even if iPhone sales this quarter were slightly lower than they were during the same quarter a year-ago, it still stands to reason that Apple, as of March 26, will have already sold its 500 millionth iPhone. Note that even if iPhone sales this quarter come in 10% lower than they were last year, the 500 millionth iPhone would have been sold by March 15.

That's certainly impressive considering that Jobs, when introducing the original iPhone, said that Apple's 2008 goal was simply to sell 10 million units.

As a final note, Forbes also put together this handy chart mapping the iPhone's impressive growth over the past few years.