Pi Day 2026 is celebrated every year on March 14, recognizing the importance of the mathematical constant π, also known as pi. Pi enthusiasts around the world celebrate this day in honor of their mathematical heritage. Visible around the world, this interactive and colorful holiday logo commemorates the significance of this mathematical innovation.
what is pi
Pi is the ratio between the circumference of a circle and its diameter, the first three and most recognized digits of which are 3.14. π is an irrational number that is used in many formulas across mathematics and physics. This means that its decimal representation is non-terminating and non-repeating.
Google’s holiday logo description states: “This holiday logo celebrates the numerical constant pi (π) and highlights the basic geometry that was first used to calculate its limits. Long before modern technology, the Greek mathematician Archimedes popularized the innovative approach.”
History and meaning of pi
Several mathematicians have calculated the value of pi using various methods, including Archimedes, Fibonacci, François Viète, Adriaan van Roomen, and Gottfried Wilhelm Leibniz. However, it was the Welsh mathematician William Jones who introduced the Greek letter π in 1706 to represent the ratio of the circumference of a circle.
Around 250 BC, the Greek mathematician Archimedes approximated the value of pi by inserting a circle between two 96-sided polygons to determine its exact upper and lower limits.
The earliest known official or large-scale celebration of Pi Day dates back to 1988. It was American physicist Larry Shaw who organized the first major Pi Day celebration at the San Francisco Exploratorium, which still hosts Pi Day celebrations today. Pi Day became a national celebration throughout the United States after the US House of Representatives passed a non-binding resolution (HRES 224) on March 12, 2009, recognizing March 14 as National Pi Day.
As a tradition, people eat pie on Pi Day because the two words are homophones. Since pies are usually round, this dish serves as an ideal way to celebrate Pi Day.
Who holds the Guinness World Record for memorizing the most digits of pi?
Indian man Rajveer Meena holds the record for memorizing the most decimal places of pi, up to 70,000 at VIT University, Vellore, India, on March 21, 2015.
