Pi Day is on March 14, and any day that combines fun, education, and pie is a day worth celebrating! Pi, also known by the Greek letter “π,” is a constant value used in math that represents the ratio of a circumference of a circle to its diameter, which is just about 3.14….15…9265359… (and so on). Not only that, but the fourteenth of March is also Albert Einstein’s birthday, so all together it’s nothing short of a mathematician’s delight.

## When is Pi Day 2025?

The beautiful constant pi (π) is celebrated by mathematicians around the world on National Pi Day on March 14.

## History of Pi Day

To learn about pi, we need to go back a few thousand years and learn about this elusive number. The value of pi was first calculated by Archimedes of Syracuse (287–212 BC), one of the greatest mathematicians of the ancient world.

However, it was first baptized with the Greek letter as its name when William Oughtred called it as such in his works dating back to 1647, later embraced by the scientific community when Leonhard Euler used the symbol in 1737.

But how did Pi Day end up in a country-wide phenomenon? For that, we need to travel to the Exploratorium in 1988 San Francisco, where it was thought up by physicist Larry Shaw.

Shaw linked March 14 with the first digits of pi (3.14) in order to organize a special day to bond the Exploratorium staff together, where he offered fruit pies and tea to everyone starting at 1:59 pm, the following three digits of the value. A few years later, after Larry’s daughter, Sara, remarked that the special date was also the birthday of Albert Einstein, they started celebrating the life of the world-famous scientist.

Pi Day became an annual Exploratorium tradition that still goes on today, and it didn’t take long for the idea to grow exponentially, hitting a peak on March 12, 2009, when the U.S Congress declared it a national holiday.

Now, celebrated by math geeks all around the circumference of the world, Pi Day became a pop culture phenomenon, with several places partaking in the activities, antics, observations and all the pie eating they can.

## National Pi Day Deals

Here’s some of the deals available on National Pi Day.

**7-Eleven**

7-Eleven stores are serving up large pizzas for the magical price of $3.14 on National Pi Day. You can grab yours in-store through the loyalty program, in the 7-Eleven app, or via the 7NOW delivery app.

**Blaze Pizza**

Blaze Pizza is offering 11-inch pizzas for… you guessed it…$3.14. To be eligible you need to download their app, set up an awards account, and set your favorite Blaze Pizza location. Once you’ve done all that you can claim your pizza at any point between now and April 12.

**Potbelly Sandwich Shop**

The good folks over at Potbelly Sandwich Shop have taken a slightly different approach to Pi Day. They are giving 314 Perks members a free chicken pot pie soup. Check the app to see if you’re one of the lucky winners.

**Aperol Spritz**

This is one of the more unusual Pi Day offers we came across. Aperol Spritz wants to be the drink that you wash your pie down with and are offering $3.14 off an Aperol Spritz kit. Those of legal age can redeem the offer by visiting Reserve Bar’s website and entering the code APEROLSPRITZ. They are also supporting the non-profit Another Round, Another Rally, with a donation of $31,415.

**Your Pie**

Here’s another $3.14 offer. This time Your Pie is offering a $3.14 discount on a 10-inch pizza. Your Pie Rewards Members will receive the offer from Sunday through to Tuesday.

**Pilot Flying J**

Pilot Flying J travel centers are getting in on the action. You can grab an extra-large, handmade whole pizza pie for $9.99. The deal can be accessed via their app up until March 14 and is redeemable at more than 350 participating venues.

**Boston Market**

Grab yourself a Pot Pie for $3.14 at Boston Market on National Pi Day. That‘s a discount of more than 50% so it’s a good one for your bank account as well as your belly.

**Goldbelly**

If you’re looking for something a little sweeter, then check out Goldbelly. They are “nerding out” for Pi Day and are offering up to 30% off on some of their most popular pies. Check out all the deals on their website.

## Pi Day timeline

Larry Shaw celebrates Pi Day for the first time.

The U.S Congress declared March 14 National Pi Day.

The first ten digits of pi were achieved on 9:26:53 a.m. (3/14/15/92653)

Larry Shaw passes away as Pi Day leaves its mark on pop culture.

## Pi Day - Survey Results

Data according to a top Market Research Agency:

WHICH ARE THE CORRECT DIGITS FOR PI?

3.1415926535 (50%)

Other guesses (50%)

## Traditions of the day

Pi Day gives math enthusiasts the opportunity to celebrate their love for numbers and the enigma that is the infinite pi.

Since 1988, the day has been celebrated at the San Francisco Exploratorium. The first celebration was organized by Larry Shaw, who worked as a physicist at the center. The staff participated by marching around the exploratorium and consuming fruit pies. This tradition has lived on since. Math lovers talk about math, host get-togethers, and have pi recital competitions. In schools, teachers arrange scavenger hunts, pie bake sales, and even Pi Day workouts to stimulate more interest in learning and practicing mathematics. Those folks who work in food marketing also love to get involved, so keep your eyes peeled for some discounts, deals, and freebies on pies, it’s going to be an extra tasty day.

## By the Numbers

**14th** – of March is also Albert Einstein’s birthday

**31.4 million** – the world record held by Emma Haruka Iwao for calculating the most accurate value of pi.

**4** – the number of months it took Emma Haruka Iwao to calculate the most accurate value of pi.

**70,000** – the number of decimal places of pi memorized by Rajveer Meena in 2015.

**10** – the number of hours it took Rajveer Meena to make the world record.

**3.125** – the original number used for pi by the Babylonians.

**22.4 trillion** – the number of digits calculated by Swiss scientist Peter Trueb, using a computer.

**24** – the number of hard drives on the computer used by Peter Trueb for calculating pi.

**700,000** – the number of years it will take to recite the 22 trillion digits of pi.

**15,000** – the number of digits of pi memorized by Mark Umile in the U.S.

## Pi Day FAQs

### Why is pi important?

Pi is very important for calculations in math, engineering, construction, physics and space exploration. Many often consider pi the most important number in all of mathematics.

### Which pie should I bake for Pi Day?

Any you’d like. We do not play favorites when pie is concerned. Pies are really simple to make and can be made with several sweet or savory fillings. Apple Pie, Chicken Pot Pie, Pizza pie, be our guest!

### Are there any places that give Pi Day deals?

Check restaurants, supermarkets and bakeries over on the Internet for special Pi Day deals. Places like Whole Foods, Boston Market and several pizza chains across the country have special day-long sales.

## Pi Day Activities

### Enjoy pie of course

Pi is a homophone of pie: the 2 words are pronounced similarly, but are spelled differently and mean different things. Celebrate Pi Day by eating lots of pie! Pizza, cherry, apple, you name it!

### Throw a potluck party

Everyone loves to show off their family pie recipe. Make it a potluck and everyone will be inclined to bring their favorite pie to Pi Day, whether it's a pizza pie, a pot pie, a savory pie, or a sweet pie. Make a playlist that features songs like "I Like Pie, I Like Cake" and "American Pie.”

### Try making a new pie

Ever tried to make a pie before? Now's your chance to bake your very own. Not into the sweet stuff? Don't worry, there are various savory pie recipes out there so that everyone can enjoy the warm buttery flakiness that comes with a fresh baked pie.

## 5 Facts About Pi

### People compete in memorizing it

Rajveer Meena has the record for memorizing the most decimal places of pi at 70,000.

### It’s used as stress tests for computers

Computing pi is a kind of “digital cardiogram” for computers.

### A Givenchy men’s cologne is named pi

So you can smell like pi too if you are the intellectual and visionary kind.

### It has other names

Pi can also be named “Archimedes’ constant,” or “Ludolph’s number.

### It has been used by heroes

Spock foils the evil computer by having it calculate pi’s value in Star Trek’s episode “Wolf in the Fold”

## Why We Love Pi Day

### Pi is infinitely cool

Pi (π) is the ratio of a circle’s circumference to its diameter — and amazingly for all circles of any size, pi will always be the same. Pi is an "irrational number," meaning its exact value is completely unknown. Scientists have calculated billions of digits starting with 3.14159265358979323…, but no recognizable pattern ever emerges. We could continue on and on until infinity and we'd still have no idea what digit might emerge next.

### Pi sounds like pie

If you are a nerd that likes pies this holiday is pretty much the best combination of the most interesting things in life: pie and mathematics. And of course that means that in order to celebrate abstract mathematical items that are somewhat irrational the obvious solution is to incorporate pie into the holiday.

### Pi links mathematics to the real world

Maybe when you were in math class, you stared off into space wondering why on earth 'logs' or 'proofs' mattered so much. Pi is the answer, well at least, one of the things that links math back to real world uses. Because pi is linked to circles it is also linked to cycles, things like calculating waves, ebb and flow, the oceans tides, electromagnetic waves and much more. In addition, many natural world phenomena can also be calculated with pi — like the shape of rivers, the disc of the sun, the spiral of DNA and even the pupil of an eye.

## Pi Day dates

Year | Date | Day |
---|---|---|

2025 | March 14 | Friday |

2026 | March 14 | Saturday |

2027 | March 14 | Sunday |

2028 | March 14 | Tuesday |

2029 | March 14 | Wednesday |