SQL AVG Function

The SQL AVG function returns the average value within a table or group. In this section, we’ll use the HumanResource.Employee table for our examples:

Using sample data above, AVG calculates the average SickLeaveHours amount for the entire table:

SELECT AVG(sickleavehours) AVGSickLeaveHours 
  FROM HumanResources.Employee

When used with GROUP BY, AVG returns the average value within a group. You can see this in this query showing the maximum SickLeaveHours by JobTitle: 

SELECT JobTitle 
 , AVG(sickleavehours) AS AVGSickLeaveHours 
FROM HumanResources.Employee 
GROUP BY JobTitle 
ORDER BY JobTitle; 

Additional SQL AVG Resources  

To learn more, check out these useful resources: 

• SQL GROUP BY Guide
• How to Calculate a Running Total 
• SQL SUM Function
• The New SQL Server Approximate Count Distinct Function