files/en-us/web/javascript/reference/global_objects/math/pi/index.md

metadata

title: Math.PI
short-title: PI
slug: Web/JavaScript/Reference/Global_Objects/Math/PI
page-type: javascript-static-data-property
browser-compat: javascript.builtins.Math.PI
sidebar: jsref

The Math.PI static data property represents the ratio of the circumference of a circle to its diameter, approximately 3.14159.

{{InteractiveExample("JavaScript Demo: Math.PI")}}

function calculateCircumference(radius) {
  return 2 * Math.PI * radius;
}

console.log(Math.PI);
// Expected output: 3.141592653589793

console.log(calculateCircumference(10));
// Expected output: 62.83185307179586

Value

$$\mathrm{𝙼𝚊𝚝𝚑.𝙿𝙸}=\pi \approx 3.14159\backslash mathtt\{Math.PI\}\; =\; \backslash pi\; \backslash approx\; 3.14159$$

{{js_property_attributes(0, 0, 0)}}

Description

Because PI is a static property of Math, you always use it as Math.PI, rather than as a property of a Math object you created (Math is not a constructor).

Examples

Using Math.PI

The following function uses Math.PI to calculate the circumference of a circle with a passed radius.

function calculateCircumference(radius) {
  return Math.PI * (radius + radius);
}

calculateCircumference(1); // 6.283185307179586

Specifications

{{Specifications}}

Browser compatibility

{{Compat}}

See also

• {{jsxref("Math")}}