Math.round() - JavaScript - MDN - Mozilla

• Skip to main content
• Skip to search

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.

• Learn more
• See full compatibility
• Report feedback

The Math.round() static method returns the value of a number rounded to the nearest integer.

In this article

• Try it
• Syntax
• Description
• Examples
• Specifications
• Browser compatibility
• See also

Try it

console.log(Math.round(0.9)); // Expected output: 1 console.log(Math.round(5.95), Math.round(5.5), Math.round(5.05)); // Expected output: 6 6 5 console.log(Math.round(-5.05), Math.round(-5.5), Math.round(-5.95)); // Expected output: -5 -5 -6

Syntax

jsMath.round(x)

Parameters

x

A number.

Return value

The value of x 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-increments away 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 as Math.floor(x + 0.5). When x is -0, or -0.5 ≤ x < 0, Math.round(x) returns -0, while Math.floor(x + 0.5) returns 0. However, neglecting that difference and potential precision errors, Math.round(x) and Math.floor(x + 0.5) are generally equivalent.

Because round() is a static method of Math, you always use it as Math.round(), rather than as a method of a Math object you created (Math has no constructor).

Examples

Using round

jsMath.round(-Infinity); // -Infinity Math.round(-20.51); // -21 Math.round(-20.5); // -20 Math.round(-0.1); // -0 Math.round(0); // 0 Math.round(20.49); // 20 Math.round(20.5); // 21 Math.round(42); // 42 Math.round(Infinity); // Infinity

Specifications

Specification
ECMAScript® 2026 Language Specification# sec-math.round

Browser compatibility

See also

• Number.prototype.toPrecision()
• Number.prototype.toFixed()
• Math.abs()
• Math.ceil()
• Math.floor()
• Math.sign()
• Math.trunc()

Help improve MDN

Was this page helpful to you? Yes No Learn how to contribute

This page was last modified on ⁨Jul 10, 2025⁩ by MDN contributors.

View this page on GitHub • Report a problem with this content Filter sidebar

1. Standard built-in objects
2. Math
3. Static methods
   1. abs()
   2. acos()
   3. acosh()
   4. asin()
   5. asinh()
   6. atan()
   7. atan2()
   8. atanh()
   9. cbrt()
   10. ceil()
   11. clz32()
   12. cos()
   13. cosh()
   14. exp()
   15. expm1()
   16. f16round()
   17. floor()
   18. fround()
   19. hypot()
   20. imul()
   21. log()
   22. log1p()
   23. log2()
   24. log10()
   25. max()
   26. min()
   27. pow()
   28. random()
   29. round()
   30. sign()
   31. sin()
   32. sinh()
   33. sqrt()
   34. sumPrecise()
   35. tan()
   36. tanh()
   37. trunc()
4. Static properties
   1. E
   2. LN2
   3. LN10
   4. LOG2E
   5. LOG10E
   6. PI
   7. SQRT1_2
   8. SQRT2