# ATAN

The ATAN function returns the arctangent, or inverse tangent, of a number. It is commonly used in trigonometry and geometry to calculate angles based on the tangent of a right-angled triangle's sides.

## Syntax

=ATAN(`number`

)

`number` | The tangent for which to find the arctangent. | |

`notes` | The ATAN function returns the angle in radians | which can be converted to degrees by multiplying by (180/π) or using the RADIANS and DEGREES functions. |

## About ATAN

When you're dealing with angles and need to invert the tangent to find an angle based on the tangent of sides of a right-angled triangle, ATAN in Excel is the go-to tool. It's widely used in trigonometry, geometry, and various mathematical applications to determine angles based on the tangent of the sides of a right-angled triangle. The function returns the arctangent of a number, providing the angle in radians, which can be converted to degrees, if necessary. ATAN facilitates precise angle calculations, allowing for accurate geometric and trigonometric analysis within Excel.

## Examples

To find the arctangent of 0.5, you would use the formula: =ATAN(0.5)

If the tangent of an angle θ is 0.75, you can find the angle in radians using: =ATAN(0.75)

For the tangent value of -1, you can calculate the arctangent by entering: =ATAN(-1)

## Questions

**What does the ATAN function return?**

The ATAN function returns the arctangent of a number in radians, representing the angle whose tangent is the specified number.

**How can I convert the result of the ATAN function to degrees?**

To convert the angle from radians to degrees, you can multiply the result of the ATAN function by (180/π) or use the RADIANS and DEGREES functions in Excel.

## Related functions

ATAN2

TAN

ATANH

TANH

SIN

COS