sin()

The sin() CSS function is a trigonometric function that returns the sine of a number, which is a value between -1 and 1. The function contains a single calculation that must resolve to either a <number> or an <angle> by interpreting the result of the argument as radians. That is, sin(45deg), sin(0.125turn), and sin(3.14159 / 4) all represent the same value, approximately 0.707.

Syntax

css

/* Single <angle> values */
width: calc(100px * sin(45deg));
width: calc(100px * sin(0.25turn));
width: calc(100px * sin(1.0471967rad));

/* Single <number> values */
width: calc(100px * sin(63.673));
width: calc(100px * sin(2 * 0.125));

/* Other values */
width: calc(100px * sin(pi / 2));
width: calc(100px * sin(e / 4));

Parameter

The sin(angle) function accepts only one value as its parameter.

angle

A calculation which resolves to a <number> or an <angle>. When specifying unitless numbers they are interpreted as a number of radians, representing an <angle>

Return value

The sine of an angle will always return a number between −1 and 1.

  • If angle is infinity, -infinity, or NaN, the result is NaN.
  • If angle is 0⁻, the result is 0⁻.

Formal syntax

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

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

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

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

<calc-constant> = 
  e          |
  pi         |
  infinity   |
  -infinity  |
  NaN

Examples

Changing box sizes

In this example, sin(30deg) will return 0.5, making the box have a 50px width and a 50px height.

css

div {
  background-color: red;
  width: calc(sin(30deg) * 100px);
  height: calc(sin(30deg) * 100px);
}

Controlling animation duration

Another use case is to control the animation-duration, reducing the duration based on the sine value. In this case, the animation duration will be 1s.

css

div {
  animation-name: myAnimation;
  animation-duration: calc(sin(0.25turn) * 1s);
}

Specifications

Specification
CSS Values and Units Module Level 4
# trig-funcs

Browser compatibility

BCD tables only load in the browser

See also