ATAN2 function

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.

Syntax

ATAN2(x_num,y_num)

X_num     is the x-coordinate of the point.

Y_num     is the y-coordinate of the point.

Remarks

  • 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 the #DIV/0! error value.

  • To express the arctangent in degrees, multiply the result by 180/PI( ) or use the DEGREES function.

Examples

Formul a

Description (Result)

=ATAN2(1, 1)

Arctangent of the point 1,1 in radians, pi/4 (0.785398)

=ATAN2(-1, -1)

Arctangent of the point -1,-1 in radians, -3*pi/4 (-2.35619)

=ATAN2(-1, -1)*180/PI()

Arctangent of the point 1,1 in degrees (-135)

=DEGREES(ATAN2(-1, -1))

Arctangent of the point 1,1 in degrees (-135)

Expand your skills
Explore training
Get new features first
Join Office Insiders

Was this information helpful?

Thank you for your feedback!

Thank you for your feedback! It sounds like it might be helpful to connect you to one of our Office support agents.

×