What is Pi Day?
Pi Day is celebrated on March 14th (3/14) around the world. Pi (Greek letter "π") is the symbol used in mathematics to represent a constant — the ratio of the circumference of a circle to its diameter — which is approximately 3.14159.
Pi has been calculated to over 100 trillion digits beyond its decimal point. As an irrational and transcendental number, it will continue infinitely without repetition or pattern.
"Mathematics is the music of reason." – James Joseph Sylvester
Find Your Number in Pi
Does your birthday, lucky number, or PIN appear in the first 1,000 digits of Pi? Enter a sequence below to find out!
The Pi Memory Game
How many digits of Pi can you remember? Watch the sequence, then type it in. It gets longer every round!
Memorize this:
Your turn! Enter the sequence:
Game Over!
You remembered 0 digits.
Fun Facts About Pi
Einstein's Birthday
March 14 is not only Pi Day but also the birthday of the legendary theoretical physicist Albert Einstein, born in 1879.
Memory Record
The Guinness World Record for memorizing digits of Pi belongs to Rajveer Meena, who recited 70,000 decimal places blindfolded in 2015.
Ancient Origins
Ancient civilizations, including the Babylonians and Egyptians, calculated rough approximations of Pi over 4,000 years ago.
Supercomputer Limits
In 2024, researchers calculated Pi to 105 trillion digits using massive computing power, taking 75 days to complete.
Mirror Magic
If you write 3.14 on a piece of paper and hold it up to a mirror, it looks somewhat like the word "PIE".
Practical Uses
NASA only needs about 15 digits of Pi for its most precise calculations, including plotting the orbits of spacecraft across the solar system.