Baseline 2023

Newly available

Since December 2023, this feature works across the latest devices and browser versions. This feature might not work in older devices or browsers.

The sqrt() CSS function is an exponential function that returns the square root of a number.

The function pow(x, 0.5) is equivalent to sqrt(x).


/* A <number> value */
width: calc(100px * sqrt(9)); /*  300px */
width: calc(100px * sqrt(25)); /*  500px */
width: calc(100px * sqrt(100)); /* 1000px */


The sqrt(x) function accepts only one value as its parameter.


A calculation which resolves to a <number> greater than or equal to 0.

Return value

Returns a <number> which is the square root of x.

  • if x is +∞, the result is +∞.
  • If x is 0⁻, the result is 0⁻.
  • If x is less than 0, the result is NaN.

Formal syntax

<sqrt()> = 
sqrt( <calc-sum> )

<calc-sum> =
<calc-product> [ [ '+' | '-' ] <calc-product> ]*

<calc-product> =
<calc-value> [ [ '*' | '/' ] <calc-value> ]*

<calc-value> =
<number> |
<dimension> |
<percentage> |
<calc-keyword> |
( <calc-sum> )

<calc-keyword> =
e |
pi |
infinity |
-infinity |


Scale sizes based on square root

This example shows how you can use the sqrt() function to calculate sizes.


<div class="boxes">
  <div class="box">50px</div>
  <div class="box one">100px</div>
  <div class="box two">150px</div>
  <div class="box three">200px</div>


Here we are using CSS custom properties to define the sizes to be used. First, we declare the first size (--size-0), which is then used to calculate the other sizes.

  • --size-1 is calculated by multiplying the value of --size-0 (50px) by the square root of 4 (2), which results in 100px.
  • --size-2 is calculated by multiplying the value of --size-0 (50px) by the square root of 9 (3), which results in 150px.
  • --size-3 is calculated by multiplying the value of --size-0 (50px) by the square root of 16 (4), which results in 200px.
:root {
  --size-0: 50px;
  --size-1: calc(var(--size-0) * sqrt(4)); /*  100px */
  --size-2: calc(var(--size-0) * sqrt(9)); /*  150px */
  --size-3: calc(var(--size-0) * sqrt(16)); /*  200px */

The sizes are then applied as the width and height values of the selectors.

.one {
  width: var(--size-1);
  height: var(--size-1);
.two {
  width: var(--size-2);
  height: var(--size-2);
.three {
  width: var(--size-3);
  height: var(--size-3);



CSS Values and Units Module Level 4
# exponent-funcs

Browser compatibility

BCD tables only load in the browser

See also