Celebrating Pi Day 14 Mar 2025

Calculating the ratio of a circle"s circumference to its diameter is as easy as pi. Today is Pi Day, an event that celebrates this mathematical constant. This date was chosen because 3, 1 and 4 are the first three significant figures of pi (π) when it is written out. Pi is an irrational number, which means that it can"t be written as a fraction. When written out, its decimal representation goes on infinitely without repeating. The oldest attempts to calculate pi date back to ancient Babylon and Egypt, around 1,900 BCE.

© David Herraez Calzada/plainpicture

palette

Today in History

A beautiful labyrinth
14 Mar 2024Happy Pi Day!
14 Mar 2026Celebrating Pi Day

More Desktop Wallpapers:

Peek-a-boo, I see you!
A postcard-perfect landscape
5 Aug 2025Tide pools in La Jolla, California, United States
20 Aug 2025The citadel in Bonifacio, Southern Corsica, France
23 Mar 2026World Meteorological Day
12 Jan 2024Bukhansan National Park, South Korea
11 Oct 2025World Migratory Bird Day
Fly me to the moon
13 Jun 2025Vila Franca Islet, São Miguel Island, Azores, Portugal
Grand slam tournament
24 Dec 2024Silent night, sparkling lights and hearts full of joy
22 Mar 2025Happy World Water Day!
2 Apr 2025Sandstone formations in the badlands near Caineville, Utah, United States
28 Dec 2024Green sea turtle
Remembering D-Day
Keep practising, little guy
19 May 2025Mount Hamilton, San Francisco Bay Area, California, United States
26 Jun 2025Horse Head Rock, New South Wales, Australia
12 May 2025An iris garden in Tokyo, Japan
The lonely castle
Pick your paradise
Let’s protect our turtles
Clouds dance above Sundance
12 Jan 2025Crescent-tail bigeye fish, Great Barrier Reef, Australia
The sprout with amazing potential
17 Jun 2024Green-crowned brilliant hummingbird
Festival fever
8 Aug 2025Bristol International Balloon Fiesta
28 Nov 2023Giving Tuesday
Big Bends birthday bash