ATN2 (Transact-SQL)

Applies to: SQL Server Azure SQL Database Azure SQL Managed Instance Azure Synapse Analytics Analytics Platform System (PDW) SQL analytics endpoint in Microsoft Fabric Warehouse in Microsoft Fabric

Returns the angle, in radians, between the positive x-axis and the ray from the origin to the point (y, x), where x and y are the values of the two specified float expressions.

Transact-SQL syntax conventions


ATN2 ( float_expression , float_expression )  


To view Transact-SQL syntax for SQL Server 2014 (12.x) and earlier versions, see Previous versions documentation.


An expression of data type float.

Return types



The following example calculates the ATN2 for the specified x and y components.

DECLARE @x FLOAT = 35.175643, @y FLOAT = 129.44;  
SELECT 'The ATN2 of the angle is: ' + CONVERT(VARCHAR, ATN2(@y, @x));  

Here is the result set.

The ATN2 of the angle is: 1.30545                         
(1 row(s) affected)  

See also

CAST and CONVERT (Transact-SQL)
float and real (Transact-SQL)
Mathematical Functions (Transact-SQL)