Math.cos()

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since July 2015.

The Math.cos() static method returns the cosine of a number in radians.

Try it

function getCircleX(radians, radius) {
  return Math.cos(radians) * radius;
}

console.log(getCircleX(1, 10));
// Expected output: 5.403023058681398

console.log(getCircleX(2, 10));
// Expected output: -4.161468365471424

console.log(getCircleX(Math.PI, 10));
// Expected output: -10

Syntax

js
Math.cos(x)

Parameters

x

A number representing an angle in radians.

Return value

The cosine of x, between -1 and 1, inclusive. If x is Infinity, -Infinity, or NaN, returns NaN.

Description

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

Examples

Using Math.cos()

js
Math.cos(-Infinity); // NaN
Math.cos(-0); // 1
Math.cos(0); // 1
Math.cos(1); // 0.5403023058681398
Math.cos(Math.PI); // -1
Math.cos(2 * Math.PI); // 1
Math.cos(Infinity); // NaN

Specifications

Specification
ECMAScript® 2025 Language Specification
# sec-math.cos

Browser compatibility

Report problems with this compatibility data on GitHub
desktopmobileserver
Chrome
Edge
Firefox
Opera
Safari
Chrome Android
Firefox for Android
Opera Android
Safari on iOS
Samsung Internet
WebView Android
WebView on iOS
Deno
Node.js
cos

Legend

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Full support
Full support

See also