The value of π\pi π comes from the ratio of a circle’s circumference to its diameter.

Quick Scoop

  • π\pi π is defined as

π=circumference of a circlediameter of that circle\pi =\frac{\text{circumference of a circle}}{\text{diameter of that circle}}π=diameter of that circlecircumference of a circle​

and this ratio is the same for every circle, no matter how big or small.

  • Numerically, this ratio is about 3.14159, and we often use 3.14 or 22/7 as handy approximations in everyday math.
  • π\pi π is an irrational number, meaning its decimal part goes on forever without repeating in a pattern.

Tiny story to picture it

Imagine you wrap a string once around any round plate, then measure that string and compare it to the plate’s straight‑across diameter.
No matter which plate you choose, the “around” length will always be a little more than three times the “across” length—that “little more than three” is exactly what we call π\pi π.

In forum discussions, when people ask “the value of pi comes from what ratio,” the go‑to answer is:
“From the ratio of a circle’s circumference to its diameter.”

TL;DR: The value of pi comes from the ratio of a circle’s circumference to its diameter.

Information gathered from public forums or data available on the internet and portrayed here.