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The Math.fround() function returns the nearest single precision float representation of a number.




A number.

Return value

The nearest single precision float representation of the given number.


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


Using Math.fround()

Math.fround(0);     // 0
Math.fround(1);     // 1
Math.fround(1.337); // 1.3370000123977661
Math.fround(1.5);   // 1.5
Math.fround(NaN);   // NaN


This can be emulated with the following function, if Float32Array are supported:

Math.fround = Math.fround || (function (array) {
  return function(x) {
    return array[0] = x, array[0];


Specification Status Comment
ECMAScript 2015 (6th Edition, ECMA-262)
The definition of 'Math.fround' in that specification.
Standard Initial definition.
ECMAScript 2017 Draft (ECMA-262)
The definition of 'Math.fround' in that specification.

Browser compatibility

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari
Basic support 38 26 (26) No support 25 7.1
Feature Android Chrome for Android Firefox Mobile (Gecko) IE Mobile Opera Mobile Safari Mobile
Basic support No support (Yes) (Yes) No support No support 8

See also

Document Tags and Contributors

 Last updated by: eduardoboucas,