Pi Pages on the Web

Web pages come and go, but we try to keep the following list up to date. If you find a link that doesn't work, please let us know.


Basic Information

BBC Article About Pi

David Blatner, author of The Joy of Pi, wrote a short article about pi for the BBC in England.

The Many Digits of Pi

If you want to download digits of pi, check out these sites:

Updates to The Pi Pages

"The story of pi reflects the most seminal, the most serious and sometimes the silliest aspects of mathematics." So say Lennart Berggren, Jonathan Borwein and Peter Borwein in their new book, Pi : A Source Book. Their Web site offers comprehensive pi links and meat for the mathematically minded.

The Ridiculously Enchanced Pi Page

Come celebrate National Pi Day (March 14, of course) at the Exploratorium. Find out how to participate on what is also Einstein's birthday! John Tierney also wrote a nice piece about pi day at The New York Times.

How Many Digits of Pi Do We Really Need?

A NASA/JPL scientist explains why even astrophysicists need only 15 digits of pi.

Pi: The Movie

The Web companion to Darren Aronofsky's fascinating film "Pi". You can also find information and links about the stock market, Kabbalah, migranes, and a number of other topics relating to the movie. You can also read a short article about this movie written by Joy of Pi author, David Blatner, published in The Seattle Weekly.

Elias' Pi Page

Along with pi fun and facts, you'll also find the binary decimal expansion of pi. From the binary coding you can also see and hear pi -- a great twist!

Pi Approximation Day

Find out what pi approximation day is, and how to celebrate it!

Pi Approximation Contest

Did you know that 3 + 4/28 - 1/(790 + 5/6) is ia pretty good approximation of pi? Not only that, but it uses all the digits between zero and nine! Check out more cool approximations and submit your own to the contest!

Replace Pi with Tau?

Michael Hartl thinks we should use tau (2pi) instead of pi. Interesting points. He refers also to this article called "Pi is Wrong!"

Articles about Pi Day and Pi

How to observe Pi Day

Sasha Volokh of Emory Law School includes fun poems (or piems or pi-ems) for Pi Day.

Washington Post: Happy Pi Day, fellow nerds!

A fun article about pi day in the Washington Post (focusing on the 2015 "pi day of the century" celebration, but with lots of other good stuff, too).

PBS: Geeking Out on Pi Day

PBS has a fun review of pi day, with the subtitle: "For the Love of Pi and the Tao of Tau". They added another article with great pi (and pie) images here

Time Magazine: Q&A: Why Do We Celebrate Pi Day?

Time interviewed Joy of Pi author David Blatner in this short Q&A from 2011

CNN: On Pi Day, one number 'reeks of mystery'

Here's all kinds of fun information compiled by CNN.

TIME for Kids: A Slice of Pi

A fun article for kids from TIME magazine, including a photo of the author.


Pi Through the Ages

How did the theory of pi evolve? Who devoted their lives to calculating digits of pi? From the Bible to Buffon, this site explores human exploration of the number pi.

Indiana Pi

The story is told in some depth in The Joy of Pi, but here's some more on Indiana's attempts to round up pi.

Yet Another Story of PI

A short history by Lazarus Mudehwe, with links to the Albany Pi Fan Club

Calculating Pi and Digits of Pi

The Bailey - Borwein - Plouffe Pi Algorithm

Here is the formula that allowed David Bailey, Peter Borwein and Simon Plouffe to compute the ten billioneth digit in the hexadecimal expansion of pi. If you are "non-technical" there's an explanation for you too!

How to Compute Digits of Pi

Want to test your computer's strength? Check here if you want to know more about computing pi. Look for the section entitled, "Special Numbers and Functions" and click on the section for computing pi. A little further down, under "Human Interest" is a section on the Indiana legislatin of pi. More on how to compute here.

One Billion

Pi explorers and authors Bailey and the Borwein brothers offer up an article "Ramanujan, Modular Equations, and Approximations to Pi or How to Compute One Billion Digits of Pi" in an effort to follow up on part of Ramanujan's work.

Pi and the Fibonnaci Numbers

A great description of how to calculate pi based on the Fibonnaci numbers. Background information and explanations are available.

Pi and Mathematics

Article: A Two Thousand

A discussion of the Bailey, Borwein Plouffe Algorithm written by Victor Adamchik and Stan Wagon.

Ask Dr. Math: Middle School Level PI

This is a great place to see what questions about pi Dr. Math has fielded in the past, and to ask any questions about pi that you might have. A great resource for anyone who wants to know more about pi. You can also check out the Pi FAQ organized http://forum.swarthmore.edu/dr.math/faq/faq.pi.html

Pi Page

Pi, from Wolfram.

Buffon's Needle

A good look at this classic probability problem and its relationship to pi.

Proof that Pi Exists

Ilan Vardi asks an interesting question: How can we prove that pi (as a constant) actually exists?

How Pi Connects To Quantum Mechanics

Kevin Knudson explains a fascinating connection between pi, the Wallis formula, and physics (specifically the energy states of the hydrogen atom).

Memorizing Pi

Olle's Pi Tatoo Page

Olle offers up a variety of pi tatoos.

Pi World Record Holders

A list of record-holders in the "pi memorization sport."


Antreas P. Hatzipolakis has collected Pi mnemonics from all over the world and Web (ie. sentences to memorize the first digits of pi) and poems related to pi. A great place for those who want to join clubs with pi memorization requirements!

Ivars Peterson's MathLand

As a "loyal member of the Ancient and Honorable Society of Pi Watchers" Ivars Peterson has written many account of this intrepid number. Here he discusses ways of memorizing pi.

The Memory Elixir

Fun and weird!

Pi Mysteries

Pi in Music

Charles Lucy describes LucyTuning and how pi relates to 'the natural scale of music,' including references to John "Longitude" Harrison's work on the subject.

Pi in the Bible

Check here to find out how the ancients may have encoded the numeric mysteries of the pi in the Bible.

Pi and Music

A Pi Day Song

A wonderful composition played on the violin based on mapping the first 200 digits of pi, by Steven Rochen. Watch and listen at youtube.

Pi Symphony

Lars Erickson's orchestral symphony based on the number pi (some of this was also used in The Joy of Pi audio book, published by Random House Audio, available at audible.com).

Listen to Pi

Felix Jung has created a delightful way to convert the first 10,000 digits of pi into music using a Flash-based animation.

More Pi Songs at YouTube

There are, of course, many pi tributes on YouTube, including this pi song, this short "pi is exactly three!" excerpt from The Simpsons, this keyboard pi movie, and this awesome rap. And more! Here's Mathematical Pi (sung to American Pie). Another brilliant pi rap.

Kate Bush Singing Pi

The inimitable Kate Bush includes a song about pi on her new album Aerial, in which she actually sings 100 or so digits of pi. And it's a good song!

Bill Crozier's Science Pi

Bill Crozier writes: "As an experiment, I tried in 1980 to get pi to 50 places stuck in my head by writing a song about it. It worked. I can still recite it now, 20 years later, by singing the song."

Fun with Pi

American Pi

A very funny spoof on the movies "Pi" and "American Pie." Caution: some adult themes. Of course, it's not funny unless you've also seen those movies.

Eve Andersson's Pi Trivia Game

Sound out the depths of your pi knowledge with Eve Andersson's great trivia game.

Search in 100 million digits of pi

Do you spend sleepless nights wondering where in pi your birthday or phone number show up? Wonder no more! Just type in the number sequence and voila! you'll know.

3-D Pi Images

Several people have created pi-inspired images. Here's one link with 3-D imagery, including the cowpi graphic.

Pi Greeting Cards

Send an Internet greeting card for Pi Day (3/14) from 123greetings.com

Buy pi day greeting cards from Greeting Card Universe

The Pi is Rational Page

For "proof" that pi is rational...a fun, alternative pi resource.

Various Pi Poems and Stuff from Mike Keith

Mike Keith has put together several great literary adventures related to pi, you can find them here. Plus, Mike shows how to decode pi to see a picture. Check out his cool book here!

Wacky Pi Stuff

Pi Exatext Poster

Can you imagine 5,942,157 digits of pi on a single poster? You need a magnifying glass to see the numbers, but it's quite amazing.

Pi paraphanalia

In case you need a pi T-shirt or a pi hat or a pi mug... Here's some cool pi stuff for sale!

Pi Bowties

You know you want a silk tie with a pi pattern on it!

Amazing Pi Art

Two artists take pi and turn it into art!

SneakyMath Pi Ruler

Here's a low-tech but high-fun pi ruler that lets you find the circumference or diameter of round objects.

Rocking Chair Radiuses as Easy as Pi

It turns out that pi is critical when making rocking chairs (if you don't want them to fall over)

Pi Fan Clubs

Friends of Pi

Dedicated to all things pi, this is a wonderful site of links and fun pi stuff. Similarly, check out the German site, too.

Pi Link Pages

Things to do on Pi Day in School

Pi Day at Google

On pi day (3/14, or March 14), Google changed its site logo. Awesome!

Yahoo's Pi Links

Pi Pages in Other Languages

The Zircumference Conference, 2002 (German)

Pi Home Page (Spanish)