WorksheetFunction.Atan2 Method

Excel Developer Reference

Returns the arctangent, or inverse tangent, of the specified x- and y-coordinates. The arctangent is the angle from the x-axis to a line containing the origin (0, 0) and a point with coordinates (x_num, y_num). The angle is given in radians between -pi and pi, excluding -pi.


expression.Atan2(Arg1, Arg2)

expression   A variable that represents a WorksheetFunction object.


Name Required/Optional Data Type Description
Arg1 Required Double The x-coordinate of the point.
Arg2 Required Double The y-coordinate of the point.

Return Value


  • A positive result represents a counterclockwise angle from the x-axis; a negative result represents a clockwise angle.
  • Atan2(a,b) equals Atan(b/a), except that a can equal 0 in Atan2.
  • If both x_num and y_num are 0, Atan2 returns an error value.
  • To express the arctangent in degrees, multiply the result by 180/PI( ) or use the Degrees method.

See Also