atan2()
Baseline 2023 Newly available
Since March 2023, this feature works across the latest devices and browser versions. This feature might not work in older devices or browsers.
The atan2() CSS function is a trigonometric function that returns the inverse tangent of two values between -infinity and infinity. The function accepts two arguments and returns the number of radians representing an <angle> between -180deg and 180deg.
Syntax
/* Two <number> values */ transform: rotate(atan2(3, 2)); /* Two <dimension> values */ transform: rotate(atan2(1rem, -0.5rem)); /* Two <percentage> values */ transform: rotate(atan2(20%, -30%)); /* Other values */ transform: rotate(atan2(pi, 45)); transform: rotate(atan2(e, 30)); Parameters
The atan2(y, x) function accepts two comma-separated values as its parameters. Each value can be a <number>, a <dimension>, or a <percentage>. Both values must be of the same type, although if they are <dimension> they can be of different units (example: atan2(100px, 5vw) is valid).
y-
The y-coordinate of the point. A calculation which resolves to a
<number>, a<dimension>, or a<percentage>. x-
The x-coordinate of the point. A calculation which resolves to a
<number>, a<dimension>, or a<percentage>.
Return value
Given two values x and y, the function atan2(y, x) calculates and returns the <angle> between the positive x-axis and the ray from the origin to the point (x, y).
Formal syntax
<atan2()> =
atan2( <calc-sum> , <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 |
NaN
Examples
>Rotate elements
The atan2() function can be used to rotate elements as it return an <angle>.
HTML
<div class="box box-1"></div> <div class="box box-2"></div> <div class="box box-3"></div> <div class="box box-4"></div> <div class="box box-5"></div> CSS
div.box { width: 100px; height: 100px; background: linear-gradient(orange, red); } div.box-1 { transform: rotate(atan2(3, 2)); } div.box-2 { transform: rotate(atan2(3%, -2%)); } div.box-3 { transform: rotate(atan2(-1, 0.5)); } div.box-4 { transform: rotate(atan2(1, 0.5)); } div.box-5 { transform: rotate(atan2(1rem, -0.5rem)); } Result
Specifications
| Specification |
|---|
| CSS Values and Units Module Level 4> # trig-funcs> |
Browser compatibility
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