Math.sqrt()
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.sqrt() static method returns the square root of a number. That is
Try it
function calcHypotenuse(a, b) {
return Math.sqrt(a * a + b * b);
}
console.log(calcHypotenuse(3, 4));
// Expected output: 5
console.log(calcHypotenuse(5, 12));
// Expected output: 13
console.log(calcHypotenuse(0, 0));
// Expected output: 0
Syntax
js
Math.sqrt(x)
Parameters
x-
A number greater than or equal to 0.
Return value
The square root of x, a nonnegative number. If x < 0, returns NaN.
Description
Because sqrt() is a static method of Math, you always use it as Math.sqrt(), rather than as a method of a Math object you created (Math is not a constructor).
Examples
Using Math.sqrt()
js
Math.sqrt(-1); // NaN
Math.sqrt(-0); // -0
Math.sqrt(0); // 0
Math.sqrt(1); // 1
Math.sqrt(2); // 1.414213562373095
Math.sqrt(9); // 3
Math.sqrt(Infinity); // Infinity
Specifications
| Specification |
|---|
| ECMAScript® 2026 Language Specification # sec-math.sqrt |