Pi Day and Pi Day T-shirts

Pi Day is a holiday held to celebrate the mathematical constant π (pi). Pi Day is observed on March 14 (3/14 in American date format), due to π being roughly equal to 3.14. How clever is that?

Even more clever are some of the t-shirts you can find to celebrate Pi Day, which occurs this year on a Saturday. Because of that, you might want to wear your Pi Day shirt on Friday March 13 (yes, that's the 2nd Friday the 13th this year so far!) to school or work.


Every Day Is Pi Day by naturetees



Pi Day Tees and Gifts by naturetees


Peace, Love & Pi Pink Flowers by naturetees



3.141592653 by LabelMeHappy


Irrational Pi by OddMatter


Celebrate PI DAY March 14 Women's Light T-Shirt

Q T Pi Cute Pi Sweatshirt (dark)

American Pi White T-Shirt

You Can Always Count on A Mat Large Mug