LOG10 (Transact-SQL)

Applies to: yesSQL Server (all supported versions) YesAzure SQL Database YesAzure SQL Managed Instance yesAzure Synapse Analytics yesParallel Data Warehouse

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

Topic link icon Transact-SQL Syntax Conventions

Syntax

LOG10 ( float_expression )  

Note

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

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 is 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 is the result set.

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

Examples: Azure Synapse Analytics (SQL Data Warehouse) and Parallel Data Warehouse

C: Calculating the base 10 logarithm for a value.

The following example calculates the LOG10 of the specified value.

SELECT LOG10(145.175642);  

Here is the result set.

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

See Also

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