ATAN()

A function that returns the angle, in radians, whose tangent is a specified float expression. This is also called arctangent.

Signature

ATAN ( float_expression )

Parameters

float_expression — An expression of either type float or of a type that implicitly convert to float.

Examples

SELECT ATAN(45.87) AS atanCalc1,  
    ATAN(-181.01) AS atanCalc2,  
    ATAN(0) AS atanCalc3,  
    ATAN(0.1472738) AS atanCalc4,  
    ATAN(197.1099392) AS atanCalc5;

1.5489990383480809|-1.5652718263440326|0.0|0.1462226769376524|1.5657230594360985

Run against SQL Server 16.0.4265.3 on 2026-09-13. This is the output we got, not the documentation’s.

Available on

SQL Server 2017 and later
Azure SQL Database
Azure SQL Managed Instance
Azure Synapse Analytics
Analytics Platform System (PDW)
Microsoft Fabric warehouse
Fabric SQL database

Signature and description adapted from the Microsoft SQL documentation, used under the CC BY 4.0. SQL Server and Azure are trademarks of the Microsoft group of companies. This page is not affiliated with Microsoft.