Happy Pi Day, San Francisco! We’re ready to celebrate this popular unofficial holiday honoring the mathematical constant Pi (π), which starts with 3.14159. Every March 14th (3/14), San Francisco’s Exploratorium goes all-out to celebrate the holiday that began there decades ago. Pi Day is also a good time to look for deals and discounts around town, often at pizza joints and large franchises. Read on for some 2025 Pi Day celebrations to put on your radar…
Physicist Larry Shaw founded Pi Day at San Francisco’s Exploratorium in 1988, and it has since become a nationwide holiday, recognized as the International Day of Mathematics in 2019. Pi (π) represents the ratio of a circle’s circumference to its diameter, with an infinite, non-repeating decimal starting with 3.14159. Mathematicians have tried for over 4,000 years to calculate it more precisely, but it never ends!
Pi Day at the Exploratorium
Join the Exploratorium for their 38th annual celebration of Pi Day. Festivities include performances from 12-piece brass band Mission Delirium, delicious free pie servings from the Seaglass Restaurant, hands-on Pi demos, and mathematician presentations.
Perhaps the most lively part of Pi Day is the Pi Procession at 2pm, where a crowd of people carrying the digits of Pi will circle a Pi Shrine 3.14 times. Grab a number and join the fun! Pi Day festivities are free with museum admission.
🌐 Learn more: Pi Day at the Exploratorium
📍 Location: Exploratorium – Pier 15 Embarcadero at, Green St, San Francisco, CA 94111
🗓️ When: Friday, March 14th from 11am-3pm
Pi Day deals and discounts around San Francisco
Take advantage of $3.14 Pi Day deals around San Francisco! Make sure to check participating locations before you hit the road.
7-Eleven
Pick up whole pizzas, quesadillas, and chicken tender boxes for $3.14 on Pi Day.
California Pizza Kitchen
CPK is selling $3.14 pizzas to those who sign up for CPK Rewards.
Blaze Pizza
Buy one pie and get one for $3.14 in-restaurant at Blaze Pizza.
Taco Bell
Sign up for the Taco Bell app and get access to a $3.14 Mexican Pizza on Pi Day.
Round Table Pizza
Word on the street is that Round Table Pizza is giving Royal Rewards members a $3.14 cheese pizza with purchase of a large pizza.
Pizza Hut
For $24.99 you can order the Pi Day special Pizza Charcuterie Board, which comes with two medium pizzas, eight wings, and breadsticks.
Papa John’s
If you’re a rewards member, you can buy a large or XL pizza and get a second one for $3.14. Then, keep an eye out for more deals through March 20th.
Burger King
If you’re a Royal Perks member and spend $3.14 or more on Pi Day, Burger King will give you a free Hershey’s Sundae Pie.