Remainder (%)

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 remainder (%) operator returns the remainder left over when one operand is divided by a second operand. It always takes the sign of the dividend.

Try it

console.log(13 % 5);
// Expected output: 3

console.log(-13 % 5);
// Expected output: -3

console.log(4 % 2);
// Expected output: 0

console.log(-4 % 2);
// Expected output: -0

Syntax

js
x % y

Description

The % operator is overloaded for two types of operands: number and BigInt. It first coerces both operands to numeric values and tests the types of them. It performs BigInt remainder if both operands become BigInts; otherwise, it performs number remainder. A TypeError is thrown if one operand becomes a BigInt but the other becomes a number.

For the operation n % d, n is called the dividend and d is called the divisor. The operation returns NaN if one of the operands is NaN, n is ±Infinity, or if d is ±0. Otherwise, if d is ±Infinity or if n is ±0, the dividend n is returned.

When both operands are non-zero and finite, the remainder r is calculated as r := n - d * q where q is the integer such that r has the same sign as the dividend n while being as close to 0 as possible.

Note that while in most languages, '%' is a remainder operator, in some (e.g. Python, Perl) it is a modulo operator. Modulo is defined as k := n - d * q where q is the integer such that k has the same sign as the divisor d while being as close to 0 as possible. For two values of the same sign, the two are equivalent, but when the operands are of different signs, the modulo result always has the same sign as the divisor, while the remainder has the same sign as the dividend, which can make them differ by one unit of d. To obtain a modulo in JavaScript, in place of n % d, use ((n % d) + d) % d. In JavaScript, the modulo operation (which doesn't have a dedicated operator) is used to normalize the second operand of bitwise shift operators (<<, >>, etc.), making the offset always a positive value.

For BigInt division, a RangeError is thrown if the divisor y is 0n. This is because number remainder by zero returns NaN, but BigInt has no concept of NaN.

Examples

Remainder with positive dividend

js
13 % 5; // 3
1 % -2; // 1
1 % 2; // 1
2 % 3; // 2
5.5 % 2; // 1.5

3n % 2n; // 1n

Remainder with negative dividend

js
-13 % 5; // -3
-1 % 2; // -1
-4 % 2; // -0

-3n % 2n; // -1n

Remainder with NaN

js
NaN % 2; // NaN

Remainder with Infinity

js
Infinity % 2; // NaN
Infinity % 0; // NaN
Infinity % Infinity; // NaN
2 % Infinity; // 2
0 % Infinity; // 0

Specifications

Specification
ECMAScript® 2025 Language Specification
# sec-multiplicative-operators

Browser compatibility

Report problems with this compatibility data on GitHub
desktopmobileserver
Chrome
Edge
Firefox
Opera
Safari
Chrome Android
Firefox for Android
Opera Android
Safari on iOS
Samsung Internet
WebView Android
WebView on iOS
Deno
Node.js
Remainder (%)

Legend

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Full support
Full support

See also