Update 3/14/2017: A new online version searches the first 10 million digits from the comfort of your web browser (desktop or mobile). No installation necessary! Or for more digits, use the apps below. Happy π day!

Update 4/12/2016: Peek in Pi is now available for purchase as a watch face for Android Wear devices. Install it from the Google Play Store.

Did you know that for any 7 digit number you can think of, there’s a 99.995% chance that it’s found in the first 100 million digits of pi?

Our mathematical obsession has boiled over into “Peek in Pi,” an app that lets you search for any number inside the digits of π.

A version for Android phones and tablets is available from Google Play. After initially rejecting the app as “not useful,” Apple relented and posted it to the iTunes Store. The app was designed for mobile devices (phones, tablets), but we made a desktop version as well. It’s available for Mac, Windows, and Linux.

Searching for numbers in π works on the premise that you can treat the individual digits as essentially a random sequence. With than in mind, it’s possible to calculate the chances of finding a set of digits of a given length:


These numbers were taken from this description of the math involved. Also from that page, this is the equation for how you calculate the number of digits:


We look forward to making further updates to explain how π works, and no doubt we also need to add a premium version that includes a billion digits instead of the miserly 100 million we’re offering now.

We first showed the app publicly at the Eyeo Festival back in 2012. You can see Ben talking about it here.

Happy searching!

Check out more of our work below, or drop us a line at hello@fathom.info.


Founded in 2010 by Ben Fry, Fathom Information Design works with clients to understand complex data through interactive tools and software for mobile devices, the web, and large format installations. Out of its studio in Boston, Fathom partners with Fortune 500s and non-profit organizations across sectors, including health care, education, financial services, media, technology, and consumer products.

How can we help? hello@fathom.info.