Pi Day is the annual math holiday celebrated on March 14, whose numeric date (3/14) matches the first three digits of π (about 3.14159). What began as a small 1988 procession at the San Francisco Exploratorium grew into an internet tradition of pie puns, memorized-digit bragging contests, and Einstein-themed math jokes each year.
Origin
The first Pi Day happened on March 14, 1988, organized by American physicist Larry Shaw at the San Francisco Exploratorium[1]. Staff scientists and visitors marched in a circular procession around one of the museum's rotundas and then ate fruit pies afterward, locking in the food pun that still defines the holiday[3]. Because March 14 also happens to be Einstein's birthday, Shaw's team let the day expand into a broader celebration of math and science, not just π on its own[1].
- Platform: San Francisco Exploratorium (offline origin) / math forums and blogs (online spread)
- Creator: Larry Shaw
- Date: 1988
Overview
Pi Day mixes genuine math appreciation with dumb wordplay. The joke rides on the phonetic overlap between π and pie, so posts, classroom events, and memes on March 14 pivot on pie-eating gags, pie-throwing bits, and photos of circular baked goods labeled with strings of digits[1]. Reciting memorized digits of π grew into its own bragging tradition, with self-identified math geeks posting how far they can go from memory[4].
The holiday also folds in Albert Einstein, whose birthday falls on March 14, so celebrations often stretch into a general science theme rather than just π itself[1]. Google marks the date with themed Pi Day Doodles[5], and MIT times its regular admissions decisions to Pi Day, turning the holiday into a running joke among high schoolers waiting on results[3]. Some math purists also nod to July 22 (22/7), the older fractional approximation, but the 3/14 version is the one that stuck online[4].
Frequently Asked Questions
What is Pi Day?
Pi Day is the annual math holiday on March 14 (3/14), matching the first three digits of the constant π ≈ 3.14159[1].
Where did Pi Day come from?
Physicist Larry Shaw started it at the San Francisco Exploratorium on March 14, 1988 with a circular march and a fruit-pie snack[1][3].
What does Pi Day mean?
It's a celebration of π and, by extension, math and science more broadly, helped along by the coincidence that Einstein was born on the same day[1].
How do you use Pi Day?
People bake or eat pies, post memes about circles and equations, and post how many digits of π they can recite from memory[4].
Is Pi Day still popular?
Yes, it is still an annual online tradition every March 14, boosted by Google Doodles[5] and a 2009 U.S. congressional resolution that made it 'National Pi Day'[2].
