LOG()

Returns the natural logarithm of the specified float expression in SQL Server.

Signature

-- Syntax for SQL Server, Azure SQL Database  
  
LOG ( float_expression [, base ] )

Parameters

  • float_expression — Is an expression of type float or of a type that can be implicitly converted to float.
  • base — Optional integer argument that sets the base for the logarithm.

Examples

SELECT LOG (EXP (10));
10.0
SELECT LOG(10);
2.3025850929940459

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

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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.