Web/JavaScript/Reference/Global objects/Number

Number is a primitive wrapper object used to represent and manipulate numbers like 37 or -9.25.

The Number' constructor contains constants and methods for working with numbers. Values of other types can be converted to numbers using the ' Number() function.

The JavaScript Number type is a double-precision 64-bit binary format IEEE 754 value, like double in Java or C#. This means it can represent fractional values, but there are some limits to what it can store. A Number only keeps about 17 decimal places of precision; arithmetic is subject to rounding. The largest value a Number can hold is about 1.8×10³⁰⁸. Numbers beyond that are replaced with the special Number constant Infinity.

A number literal like 37 in JavaScript code is a floating-point value, not an integer. There is no separate integer type in common everyday use. (JavaScript now has a BigInt type, but it was not designed to replace Number for everyday uses. 37 is still a Number, not a BigInt.)

Number may also be expressed in literal forms like 0b101, 0o13, 0x0A. Learn more on numeric lexical grammar here.

Description

When used as a function, Number(value) converts a string or other value to the Number type. If the value can't be converted, it returns NaN.

Literal syntax

123    // one-hundred twenty-three
123.0  // same
123 === 123.0  // true

Function syntax

Number('123')  // returns the number 123
Number('123') === 123  // true

Number("unicorn")  // NaN
Number(undefined)  // NaN

Constructor

Number(): Creates a new Number value.

Static properties

Number.EPSILON: The smallest interval between two representable numbers.
Number.MAX_SAFE_INTEGER: The maximum safe integer in JavaScript (253 - 1).
Number.MAX_VALUE: The largest positive representable number.
Number.MIN_SAFE_INTEGER: The minimum safe integer in JavaScript (-(253 - 1)).
Number.MIN_VALUE: The smallest positive representable number—that is, the positive number closest to zero (without actually being zero).
Number.NaN: Special "Not a Number" value.
Number.NEGATIVE_INFINITY: Special value representing negative infinity. Returned on overflow.
Number.POSITIVE_INFINITY: Special value representing infinity. Returned on overflow.
Number.prototype: Allows the addition of properties to the Number object.

Static methods

Number.isNaN(): Determine whether the passed value is NaN.
Number.isFinite(): Determine whether the passed value is a finite number.
Number.isInteger(): Determine whether the passed value is an integer.
Number.isSafeInteger(): Determine whether the passed value is a safe integer (number between -(253 - 1) and 253 - 1).
Number.parseFloat(string): This is the same as the global parseFloat() function.
Number.parseInt(string, [radix]): This is the same as the global parseInt() function.

Instance methods

Number.prototype.toExponential(fractionDigits): Returns a string representing the number in exponential notation.
Number.prototype.toFixed(digits): Returns a string representing the number in fixed-point notation.
Number.prototype.toLocaleString([locales [, options)]]: Returns a string with a language sensitive representation of this number. Overrides the Object.prototype.toLocaleString() method.
Number.prototype.toPrecision(precision): Returns a string representing the number to a specified precision in fixed-point or exponential notation.
Number.prototype.toString([radix]): Returns a string representing the specified object in the specified radix ("base"). Overrides the Object.prototype.toString() method.
Number.prototype.valueOf(): Returns the primitive value of the specified object. Overrides the Object.prototype.valueOf() method.

Examples

Using the Number object to assign values to numeric variables

The following example uses the Number object's properties to assign values to several numeric variables:

const biggestNum     = Number.MAX_VALUE
const smallestNum    = Number.MIN_VALUE
const infiniteNum    = Number.POSITIVE_INFINITY
const negInfiniteNum = Number.NEGATIVE_INFINITY
const notANum        = Number.NaN

Integer range for Number

The following example shows the minimum and maximum integer values that can be represented as Number object. (More details on this are described in the ECMAScript standard, chapter 6.1.6 The Number Type.)

const biggestInt  = Number.MAX_SAFE_INTEGER  //  (253 - 1) =>  9007199254740991
const smallestInt = Number.MIN_SAFE_INTEGER  // -(253 - 1) => -9007199254740991

When parsing data that has been serialized to JSON, integer values falling outside of this range can be expected to become corrupted when JSON parser coerces them to Number type.

A possible workaround is to use String instead.

Larger numbers can be represented using the BigInt type.

Using Number to convert a Date object

The following example converts the Date object to a numerical value using Number as a function:

let d = new Date('December 17, 1995 03:24:00')
console.log(Number(d))

This logs 819199440000.

Convert numeric strings and null to numbers

Number('123')     // 123
Number('123') === 123 /// true
Number('12.3')    // 12.3
Number('12.00')   // 12
Number('123e-1')  // 12.3
Number('')        // 0
Number(null)      // 0
Number('0x11')    // 17
Number('0b11')    // 3
Number('0o11')    // 9
Number('foo')     // NaN
Number('100a')    // NaN
Number('-Infinity') //-Infinity

Specifications

Specification
ECMAScript (ECMA-262)The definition of 'Number' in that specification.

Browser compatibility

The compatibility table in this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request.

Update compatibility data on GitHub

	Desktop						Mobile						Server
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet	Node.js
`Number`	Chrome Full support 1	Edge Full support 12	Firefox Full support 1	IE Full support 3	Opera Full support 3	Safari Full support 1	WebView Android Full support 1	Chrome Android Full support 18	Firefox Android Full support 4	Opera Android Full support 10.1	Safari iOS Full support 1	Samsung Internet Android Full support 1.0	nodejs Full support 0.1.100
`EPSILON`	Chrome Full support 34	Edge Full support 12	Firefox Full support 25	IE No support No	Opera Full support 21	Safari Full support 9	WebView Android Full support ≤37	Chrome Android Full support 34	Firefox Android Full support 25	Opera Android Full support 21	Safari iOS Full support 9	Samsung Internet Android Full support 2.0	nodejs Full support 0.12
`MAX_SAFE_INTEGER`	Chrome Full support 34	Edge Full support 12	Firefox Full support 31	IE No support No	Opera Full support 21	Safari Full support 9	WebView Android Full support ≤37	Chrome Android Full support 34	Firefox Android Full support 31	Opera Android Full support 21	Safari iOS Full support 9	Samsung Internet Android Full support 2.0	nodejs Full support 0.12
`MAX_VALUE`	Chrome Full support 1	Edge Full support 12	Firefox Full support 1	IE Full support 4	Opera Full support 3	Safari Full support 1	WebView Android Full support 1	Chrome Android Full support 18	Firefox Android Full support 4	Opera Android Full support 10.1	Safari iOS Full support 1	Samsung Internet Android Full support 1.0	nodejs Full support 0.1.100
`MIN_SAFE_INTEGER`	Chrome Full support 34	Edge Full support 12	Firefox Full support 31	IE No support No	Opera Full support 21	Safari Full support 9	WebView Android Full support ≤37	Chrome Android Full support 34	Firefox Android Full support 31	Opera Android Full support 21	Safari iOS Full support 9	Samsung Internet Android Full support 2.0	nodejs Full support 0.12
`MIN_VALUE`	Chrome Full support 1	Edge Full support 12	Firefox Full support 1	IE Full support 4	Opera Full support 3	Safari Full support 1	WebView Android Full support 1	Chrome Android Full support 18	Firefox Android Full support 4	Opera Android Full support 10.1	Safari iOS Full support 1	Samsung Internet Android Full support 1.0	nodejs Full support 0.1.100
`NaN`	Chrome Full support 1	Edge Full support 12	Firefox Full support 1	IE Full support 4	Opera Full support 3	Safari Full support 1	WebView Android Full support 1	Chrome Android Full support 18	Firefox Android Full support 4	Opera Android Full support 10.1	Safari iOS Full support 1	Samsung Internet Android Full support 1.0	nodejs Full support 0.1.100
`NEGATIVE_INFINITY`	Chrome Full support 1	Edge Full support 12	Firefox Full support 1	IE Full support 4	Opera Full support 3	Safari Full support 1	WebView Android Full support 1	Chrome Android Full support 18	Firefox Android Full support 4	Opera Android Full support 10.1	Safari iOS Full support 1	Samsung Internet Android Full support 1.0	nodejs Full support 0.1.100
`Number()` constructor	Chrome Full support 1	Edge Full support 12	Firefox Full support 1	IE Full support 3	Opera Full support 3	Safari Full support 1	WebView Android Full support 1	Chrome Android Full support 18	Firefox Android Full support 4	Opera Android Full support 10.1	Safari iOS Full support 1	Samsung Internet Android Full support 1.0	nodejs Full support 0.1.100
`POSITIVE_INFINITY`	Chrome Full support 1	Edge Full support 12	Firefox Full support 1	IE Full support 4	Opera Full support 3	Safari Full support 1	WebView Android Full support 1	Chrome Android Full support 18	Firefox Android Full support 4	Opera Android Full support 10.1	Safari iOS Full support 1	Samsung Internet Android Full support 1.0	nodejs Full support 0.1.100
`isFinite`	Chrome Full support 19	Edge Full support 12	Firefox Full support 16	IE No support No	Opera Full support 15	Safari Full support 9	WebView Android Full support ≤37	Chrome Android Full support 25	Firefox Android Full support 16	Opera Android Full support 14	Safari iOS Full support 9	Samsung Internet Android Full support 1.5	nodejs Full support 0.10
`isInteger`	Chrome Full support 34	Edge Full support 12	Firefox Full support 16	IE No support No	Opera Full support 21	Safari Full support 9	WebView Android Full support ≤37	Chrome Android Full support 34	Firefox Android Full support 16	Opera Android Full support 21	Safari iOS Full support 9	Samsung Internet Android Full support 2.0	nodejs Full support 0.12
`isNaN`	Chrome Full support 25	Edge Full support 12	Firefox Full support 15	IE No support No	Opera Full support 15	Safari Full support 9	WebView Android Full support ≤37	Chrome Android Full support 25	Firefox Android Full support 15	Opera Android Full support 14	Safari iOS Full support 9	Samsung Internet Android Full support 1.5	nodejs Full support 0.10
`isSafeInteger`	Chrome Full support 34	Edge Full support 12	Firefox Full support 32	IE No support No	Opera Full support 21	Safari Full support 10	WebView Android Full support ≤37	Chrome Android Full support 34	Firefox Android Full support 32	Opera Android Full support 21	Safari iOS Full support 10	Samsung Internet Android Full support 2.0	nodejs Full support 0.12
`parseFloat`	Chrome Full support 34	Edge Full support 12	Firefox Full support 25	IE No support No	Opera Full support 21	Safari Full support 9	WebView Android Full support ≤37	Chrome Android Full support 34	Firefox Android Full support 25	Opera Android Full support 21	Safari iOS Full support 9	Samsung Internet Android Full support 2.0	nodejs Full support 0.12
`parseInt`	Chrome Full support 34	Edge Full support 12	Firefox Full support 25	IE No support No	Opera Full support 21	Safari Full support 9	WebView Android Full support ≤37	Chrome Android Full support 34	Firefox Android Full support 25	Opera Android Full support 21	Safari iOS Full support 9	Samsung Internet Android Full support 2.0	nodejs Full support 0.12
`toExponential`	Chrome Full support 1	Edge Full support 12	Firefox Full support 1	IE Full support 5.5	Opera Full support 7	Safari Full support 2	WebView Android Full support 1	Chrome Android Full support 18	Firefox Android Full support 4	Opera Android Full support 10.1	Safari iOS Full support 1	Samsung Internet Android Full support 1.0	nodejs Full support 0.1.100
`toFixed`	Chrome Full support 1	Edge Full support 12	Firefox Full support 1	IE Full support 5.5	Opera Full support 7	Safari Full support 2	WebView Android Full support 1	Chrome Android Full support 18	Firefox Android Full support 4	Opera Android Full support 10.1	Safari iOS Full support 1	Samsung Internet Android Full support 1.0	nodejs Full support 0.1.100
`toLocaleString`	Chrome Full support 1	Edge Full support 12 Notes' Full support 12 Notes' Notes' Before Edge 18, numbers are rounded to 15 decimal digits. For example, `(1000000000000005).toLocaleString('en-US')` returns `"1,000,000,000,000,010"`.	Firefox Full support 1	IE Full support 5 Notes' Full support 5 Notes' Notes' In Internet Explorer 11, numbers are rounded to 15 decimal digits. For example, `(1000000000000005).toLocaleString('en-US')` returns `"1,000,000,000,000,010"`.	Opera Full support 4	Safari Full support 1	WebView Android Full support 1	Chrome Android Full support 18	Firefox Android Full support 4	Opera Android Full support 10.1	Safari iOS Full support 1	Samsung Internet Android Full support 1.0	nodejs Full support 0.1.100
`toPrecision`	Chrome Full support 1	Edge Full support 12	Firefox Full support 1	IE Full support 5.5	Opera Full support 7	Safari Full support 2	WebView Android Full support 1	Chrome Android Full support 18	Firefox Android Full support 4	Opera Android Full support 10.1	Safari iOS Full support 1	Samsung Internet Android Full support 1.0	nodejs Full support 0.1.100
`toSource` Non-standard'	Chrome No support No	Edge No support No	Firefox No support 1 — 74 Notes' No support 1 — 74 Notes' Notes' Starting in Firefox 74, `toSource()` is no longer available for use by web content. It is still allowed for internal and privileged code.	IE No support No	Opera No support No	Safari No support No	WebView Android No support No	Chrome Android No support No	Firefox Android Full support 4	Opera Android No support No	Safari iOS No support No	Samsung Internet Android No support No	nodejs No support No
`toString`	Chrome Full support 1	Edge Full support 12	Firefox Full support 1	IE Full support 3	Opera Full support 4	Safari Full support 1	WebView Android Full support 1	Chrome Android Full support 18	Firefox Android Full support 4	Opera Android Full support 10.1	Safari iOS Full support 1	Samsung Internet Android Full support 1.0	nodejs Full support 0.1.100
`valueOf`	Chrome Full support 1	Edge Full support 12	Firefox Full support 1	IE Full support 4	Opera Full support 4	Safari Full support 1	WebView Android Full support 1	Chrome Android Full support 18	Firefox Android Full support 4	Opera Android Full support 10.1	Safari iOS Full support 1	Samsung Internet Android Full support 1.0	nodejs Full support 0.1.100

Legend

Full support: Full support
No support: No support
Non-standard. Expect poor cross-browser support.': Non-standard. Expect poor cross-browser support.
See implementation notes.': See implementation notes.