In August, thanks to an infographic we shared with you from Followgram.me, we were able to see that Instagram grew twice as fast as Flickr. Swedish blogger Hans Kullin has broken down the numbers, and using a few guestimates, we’re able to see just how much faster that growth is taking place on a daily basis.

Looking at the ID numbers of photos uploaded on Instagram, Kullin determined that the photo sharing app had passed the 500 million mark, with about 4.5 million photos uploaded per day.

Taking a look at Instagram’s official statistics, with 60 photos uploaded per second (a figure which is 20 times bigger than it was last year), Kullin calculated that the total comes to almost 5.2 million photos per day. If we compare this with the figures that we saw in August, that means that Instagram has grown 300% in just the past six months.

Instagram Instagram could hit 1bn photos by April, twice as fast as Flickr managed

When we take a look at Kullin’s estimates for Flickr, the growth has slowed down considerably. This certainly doesn’t come as surprise, when the aging site has been plagued with evolving competitors, like Google+ and 500px, in stark contrast to its stagnant lack of change. In fact, the most recent announcement from Flickr, while promised many changes to come was more about all the features that are being removed.

While Flickr’s official statistic is 4.5 million photos uploaded a day, Kullin believes that is a little generous, saying it’s at 4.2m. Using Flickr’s official figure of 4.5 million, in comparison with Instagram’s 5.2 million, then Instagram is growing 1.2 times faster than Flickr, on a daily basis.

Flickr Instagram could hit 1bn photos by April, twice as fast as Flickr managed

While Instagram’s lead has diminished, it’s still far ahead of Flickr, and we can only wait and see what the latter will bring to the table to engage users. At the moment, Flickr’s only advantage that it has over other similar sites is that it acts as a huge repository of Creative Commons images. As far as social networking or mobile sharing goes, Flickr may as well not even be in the race.

Using Kullin’s estimates, Instagram could reach 1 billion photos by mid-April 2012, a figure that is remarkable considering it remains an iOS-only app, while it took Flickr over 3 years to pass that milestone. With news that Instagram is working on its Android app, and more recent rumours that we may even see a Windows Phone 7 version first, the app still has a ton of room for growth.

Flickr recently reached the 6 billion mark in August, a feat which took it 7 years, with Facebook users uploading that many photos every 2 months.

It is worth taking into consideration the fact that Flickr was launched in an environment where mobile sharing was far less common, whereas Instagram’s growth is driven by the iPhone.

Want to visualize all those photos? Check out Erik Kessel’s installation, showing us what just 24 hours worth of Flickr photos look like.