Math.round()
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.round() static method returns the value of a number rounded to the nearest integer.
Try it
console.log(Math.round(0.9));// Expected output: 1console.log(Math.round(5.95), Math.round(5.5), Math.round(5.05));// Expected output: 6 6 5console.log(Math.round(-5.05), Math.round(-5.5), Math.round(-5.95));// Expected output: -5 -5 -6Syntax
Math.round(x)Parameters
xA number.
Return value
The value ofx rounded to the nearest integer.
Description
If the fractional portion of the argument is greater than 0.5, the argument is rounded to the integer with the next higher absolute value. If it is less than 0.5, the argument is rounded to the integer with the lower absolute value. If the fractional portion is exactly 0.5, the argument is rounded to the next integer in the direction of +∞.
Note:This differs from many languages'round() functions, which often round half-incrementsaway from zero, giving a different result in the case of negative numbers with a fractional part of exactly 0.5.
Math.round(x) is not exactly the same asMath.floor(x + 0.5). Whenx is -0, or -0.5 ≤ x < 0,Math.round(x) returns -0, whileMath.floor(x + 0.5) returns 0. However, neglecting that difference and potential precision errors,Math.round(x) andMath.floor(x + 0.5) are generally equivalent.
Becauseround() is a static method ofMath, you always use it asMath.round(), rather than as a method of aMath object you created (Math has no constructor).
Examples
Using round
Math.round(-Infinity); // -InfinityMath.round(-20.51); // -21Math.round(-20.5); // -20Math.round(-0.1); // -0Math.round(0); // 0Math.round(20.49); // 20Math.round(20.5); // 21Math.round(42); // 42Math.round(Infinity); // InfinitySpecifications
| Specification |
|---|
| ECMAScript® 2026 Language Specification # sec-math.round |