Math.tan()

main Documentación oficial Licencia CC-BY-SA-2.5Descargado el 2026-08-02

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Parameters#
Return value#
Description#
Examples#
Using Math.tan()#
Math.tan() and π/2#
Using Math.tan() with a degree value#
Specifications#
Browser compatibility#
See also#

The Math.tan() static method returns the tangent of a number in radians.

```js interactive-example function getTanFromDegrees(degrees) { return Math.tan((degrees * Math.PI) / 180); }

console.log(getTanFromDegrees(0)); // Expected output: 0

console.log(getTanFromDegrees(45)); // Expected output: 0.9999999999999999

console.log(getTanFromDegrees(90)); // Expected output: 16331239353195370

## Syntax

```js-nolint
Math.tan(x)

Parameters#

x
: A number representing an angle in radians.

Return value#

The tangent of x. If x is {{jsxref("Infinity")}}, -Infinity, or {{jsxref("NaN")}}, returns {{jsxref("NaN")}}.

[!NOTE] Due to floating point precision, it's not possible to obtain the exact value π/2, so the result is always finite if not NaN.

Description#

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

Examples#

Using Math.tan()#

Math.tan(-Infinity); // NaN
Math.tan(-0); // -0
Math.tan(0); // 0
Math.tan(1); // 1.5574077246549023
Math.tan(Math.PI / 4); // 0.9999999999999999 (Floating point error)
Math.tan(Infinity); // NaN

Math.tan() and π/2#

It's not possible to calculate tan(π/2) exactly.

Math.tan(Math.PI / 2); // 16331239353195370
Math.tan(Math.PI / 2 + Number.EPSILON); // -6218431163823738

Using Math.tan() with a degree value#

Because the Math.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);
}