The Excel Averageifs function finds entries in one or more arrays, that satisfy a all of a set of supplied criteria, and returns the average (ie. the statistical mean) of the corresponding values in a further supplied array.
The function is new in Excel 2007, and so is not available in earlier versions of Excel.
The syntax of the Averageifs function is :
Where the function arguments are:
average_range    An array of numeric values (or cells containing numbers) for which the average is to be calculated. 
criteria_range1 [criteria_range2], ... 
 
Arrays of values (or ranges of cells containing values) to be tested against the respective criteria1, criteria2, ... (The supplied criteria_range arrays must all have the same length) 
criteria1, [criteria2], ... 
  The conditions to be tested against the values in criteria_range1, [criteria_range2], ... 
Wildcards
You can also use the following wildcards in textrelated criteria:
?  matches any single character
*  matches any sequence of characters
if you do actually want to find the ? or * character, type the ~ symbol before this character in your search.
eg. the condition "A*e" will match all cells containing a text string beginning with "A" and ending in "e".The supplied criteria can be either:
and can be entered into the function either directly, as values returned from other functions, or as references to cells containing values.
The Excel Averageifs function is not casesensitive. So, for example, the text strings "TEXT" and "text" will be classed as equal.
The spreadsheet below shows the quarterly sales figures for 3 sales representatives.
The Averageifs function can be used to find average sales figures for any combination of quarter, area and sales rep.
This is shown in the examples below.
A  B  C  D  

1  Quarter  Area  Sales Rep.  Sales 
2  1  North  Jeff  $223,000 
3  1  North  Chris  $125,000 
4  1  South  Carol  $456,000 
5  2  North  Jeff  $322,000 
6  2  North  Chris  $340,000 
7  2  South  Carol  $198,000 
8  3  North  Jeff  $310,000 
9  3  North  Chris  $250,000 
10  3  South  Carol  $460,000 
11  4  North  Jeff  $261,000 
12  4  North  Chris  $389,000 
13  4  South  Carol  $305,000 
To find the average quarterly sale, per person, in the North area during quarter 1:
which gives the result $174,000.
In this example, the Excel Averageifs function identifies rows where:
and calculates the average of the corresponding values from column D.
ie. this formula finds the average of the values $223,000 and $125,000 (from cells D2 and D3).
Again, using the data spreadsheet above, we can also use the Averageifs function to find the average sales figure for "Jeff", during quarters 3 and 4:
This formula returns the result $285,500.
In this example, the Excel Averageifs function identifies rows where:
and calculates the average of the corresponding values in column D.
ie. this formula finds the average of the values $310,000 and $261,000 (from cells D8 and D11).
Further examples of the Excel Averageifs function can be found on the Microsoft Office website.
The most common errors from the Excel Averageifs function are listed in the table below :
#DIV/0!   
Occurs if either:

#VALUE!    Occurs if the length of any of the supplied criteria_range arrays is not equal to the length of the average_range array. 