Math.tan()
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.
TheMath.tan() static method returns the tangent of a number in radians.
Try it
function getTanFromDegrees(degrees) { return Math.tan((degrees * Math.PI) / 180);}console.log(getTanFromDegrees(0));// Expected output: 0console.log(getTanFromDegrees(45));// Expected output: 0.9999999999999999console.log(getTanFromDegrees(90));// Expected output: 16331239353195370Syntax
Math.tan(x)Parameters
xA number representing an angle in radians.
Return value
The tangent ofx. Ifx isInfinity,-Infinity, orNaN, returnsNaN.
Note:Due to floating point precision, it's not possible to obtain the exact value π/2, so the result is always finite if notNaN.
Description
Becausetan() is a static method ofMath, you always use it asMath.tan(), rather than as a method of aMath object you created (Math is not a constructor).
Examples
Using Math.tan()
Math.tan(-Infinity); // NaNMath.tan(-0); // -0Math.tan(0); // 0Math.tan(1); // 1.5574077246549023Math.tan(Math.PI / 4); // 0.9999999999999999 (Floating point error)Math.tan(Infinity); // NaNMath.tan() and π/2
It's not possible to calculatetan(π/2) exactly.
Math.tan(Math.PI / 2); // 16331239353195370Math.tan(Math.PI / 2 + Number.EPSILON); // -6218431163823738Using Math.tan() with a degree value
Because theMath.tan() function accepts radians, but it is often easier to work with degrees, the following function accepts a value in degrees, converts it to radians and returns the tangent.
function getTanDeg(deg) { const rad = (deg * Math.PI) / 180; return Math.tan(rad);}Specifications
| Specification |
|---|
| ECMAScript® 2026 Language Specification # sec-math.tan |