Returns the correlation coefficient of the array1 and array2 cell ranges. Use the correlation coefficient to determine the relationship between two properties. For example, you can examine the relationship between a location's average temperature and the use of air conditioners.
Syntax
CORREL(array1,array2)
Array1 is a cell range of values.
Array2 is a second cell range of values.
Remarks
 If an array or reference argument contains text, logical values, or empty cells, those values are ignored; however, cells with the value zero are included.
 If array1 and array2 have a different number of data points, CORREL returns the #N/A error value.
 If either array1 or array2 is empty, or if s (the standard deviation) of their values equals zero, CORREL returns the #DIV/0! error value.
 The equation for the correlation coefficient is:
where
are the sample means AVERAGE(array1) and AVERAGE(array2).
Example
The example may be easier to understand if you copy it to a blank worksheet.
How to copy an example
 Create a blank workbook or worksheet.
 Select the example in the Help topic.
Note Do not select the row or column headers.
Fig. 1 Selecting an example from Help
 Press CTRL+C.
 In the worksheet, select cell A1, and press CTRL+V.
 To switch between viewing the results and viewing the formulas that return the results, press CTRL+` (grave accent), or on the Formulas tab, in the Formula Auditing group, click the Show Formulas button.

A 
B 
Data1 
Data2 
3 
9 
2 
7 
4 
12 
5 
15 
6 
17 
Formula 
Description (Result) 
=CORREL(A2:A6,B2:B6) 
Correlation coefficient of the two data sets above (0.997054) 
