JavaScript atan2() Method

❮ JavaScript Math Object

Example - atan2(y,x)

Assume you had a point with the (x,y) coordinates of (4,8), you could calculate the angle in radians between that point and the positive X axis as follows:

Math.atan2(8, 4);

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Definition and Usage

The atan2() method returns the arctangent of the quotient of its arguments, as a numeric value between PI and -PI radians.

The number returned represents the counterclockwise angle in radians (not degrees) between the positive X axis and the point (x, y).

Note: With atan2(), the y coordinate is passed as the first argument and the x coordinate is passed as the second argument.

Browser Support

atan2() Yes Yes Yes Yes Yes


Math.atan2(y, x)

Parameter Description
y Required. A number representing the y coordinate
x Required. A number representing the x coordinate

Technical Details

Return Value: A Number, from PI to -PI, or NaN if the value(s) are empty
JavaScript Version: ECMAScript 1

❮ JavaScript Math Object