LOG10 (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 SQL database in Microsoft Fabric

Returns the base-10 logarithm of the specified float expression.

Transact-SQL syntax conventions

Syntax

LOG10 ( float_expression )  

Arguments

float_expression
Is an expression of type float or of a type that can be implicitly converted to float.

Return Types

float

Remarks

The LOG10 and POWER functions are inversely related to one another. For example, 10 ^ LOG10(n) = n.

Examples

A. Calculating the base 10 logarithm for a variable.

The following example calculates the LOG10 of the specified variable.

DECLARE @var FLOAT;  
SET @var = 145.175643;  
SELECT 'The LOG10 of the variable is: ' + CONVERT(VARCHAR,LOG10(@var));  
GO  

Here's the result set.

The LOG10 of the variable is: 2.16189      
  
(1 row(s) affected)  

B. Calculating the result of raising a base-10 logarithm to a specified power.

The following example returns the result of raising a base-10 logarithm to a specified power.

SELECT POWER (10, LOG10(5));   

Here's the result set.

-----------  
5  
  
(1 row(s) affected)  

Examples: Azure Synapse Analytics and Analytics Platform System (PDW)

C: Calculating the base 10 logarithm for a value.

The following example calculates the LOG10 of the specified value.

SELECT LOG10(145.175642);  

Here's the result set.

-------------------  
2.16

See Also

Mathematical Functions (Transact-SQL)
POWER (Transact-SQL)
LOG (Transact-SQL)