Math.SQRT1_2

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.SQRT1_2 static data property represents the square root of 1/2, which is approximately 0.707.

Try it

function getRoot1Over2() {
  return Math.SQRT1_2;
}

console.log(getRoot1Over2());
// Expected output: 0.7071067811865476

Value

𝙼𝚊𝚝𝚑.𝚂𝚀𝚁𝚃𝟷_𝟸=12≈0.707\mathtt{Math.SQRT1_2} = \sqrt{\frac{1}{2}} \approx 0.707 Property attributes of Math.SQRT1_2

Writable	no
Enumerable	no
Configurable	no

Description

Math.SQRT1_2 is a constant and a more performant equivalent to Math.sqrt(0.5).

Because SQRT1_2 is a static property of Math, you always use it as Math.SQRT1_2, rather than as a property of a Math object you created (Math is not a constructor).

Examples

Using Math.SQRT1_2

The following function calculates the side length of a square given its diagonal length:

js
function getSquareSideLength(diagonalLength) {
  return diagonalLength * Math.SQRT1_2;
}

Specifications

Specification

ECMAScript® 2027 Language Specification
# sec-math.sqrt1_2

Browser compatibility

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This page was last modified on Nov 3, 2025 by MDN contributors.

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Standard built-in objects
Math
Static methods
Static properties
1. E
2. LN2
3. LN10
4. LOG2E
5. LOG10E
6. PI
7. SQRT1_2
8. SQRT2