Math.PI

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

$$\mathtt{\mi{Math.PI}} = \pi \approx 3.14159$$

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 2 * Math.PI * radius;
}

calculateCircumference(1);  // 6.283185307179586

Specifications

Specification	Status	Comment
ECMAScript 1st Edition (ECMA-262)	Standard	Initial definition. Implemented in JavaScript 1.0.
ECMAScript 5.1 (ECMA-262) The definition of 'Math.PI' in that specification.	Standard
ECMAScript 2015 (6th Edition, ECMA-262) The definition of 'Math.PI' in that specification.	Standard
ECMAScript 2017 Draft (ECMA-262) The definition of 'Math.PI' in that specification.	Draft

Browser compatibility

See also

• Math