π = Cd
A circle's signature
Divide any circle's circumference by its diameter. Whether it's a coin or a planet, the answer is always pi.
Infinite digits. Endless wonder.
Pi
A little number.
An infinite story.
From the simplest circle to the fabric of the universe, one constant connects it all. Meet the number that never ends.
Explore the constant
IRRATIONAL. TRANSCENDENTAL. UNIVERSAL.
IT STARTS WITH
01 / THE FUNDAMENTALS
One constant. Everywhere.
Every circle holds the same secret.
Its size doesn't change the story.
A = πr2
The space inside
Square the radius, multiply by pi, and you've found the area. A beautifully simple rule for every circle.
eiπ + 1 = 0
An unexpected reunion
Euler's identity brings five fundamental constants together in one equation: e, i, π, 1, and 0.
02 / MAKE IT TANGIBLE
Change the circle. Not the ratio.
A small experiment with a remarkably consistent result.
Give it a spin in size.
Drag to change the diameter. The circumference changes with it, but their ratio stays exactly the same.
Circumference18.850
C ÷ d3.14159…
03 / A GLIMPSE OF INFINITY
The digits go on. And on.
No final digit. No endlessly repeating block. Just an infinite decimal to explore.
Showing the first 100 of 200 available decimal places.
A UNIVERSAL LANGUAGE, WRITTEN IN NUMBERS.
04 / BEYOND THE CIRCLE
Ancient roots.
Infinite possibilities.
People have been chasing pi for thousands of years. Ancient Babylonians and Egyptians found early approximations; Archimedes trapped its value between the perimeters of polygons.
Today, pi turns up in waves, probability, physics, and places where no circle is immediately in sight. We can calculate trillions of its digits, yet a handful is enough for most everyday calculations.
A DATE TO CELEBRATE → MARCH 14 · 3/14Some things are worth going on about.
3.141592653589793238462643383279…