Returns the righttailed probability of the chisquared distribution. The χ^{2} distribution is associated with a χ^{2} test. Use the χ^{2} test to compare observed and expected values. For example, a genetic experiment might hypothesize that the next generation of plants will exhibit a certain set of colors. By comparing the observed results with the expected ones, you can decide whether your original hypothesis is valid.
Important This function has been replaced with one or more new functions that may provide improved accuracy and whose names better reflect their usage. Although this function is still available for backward compatibility, you should consider using the new functions from now on, because this function may not be available in future versions of Excel.
For more information about the new functions, see CHISQ.DIST function and CHISQ.DIST.RT function.
Syntax
CHIDIST(x,deg_freedom)
The CHIDIST function syntax has the following arguments (argument: A value that provides information to an action, an event, a method, a property, a function, or a procedure.):
 X Required. The value at which you want to evaluate the distribution.
 Deg_freedom Required. The number of degrees of freedom.
Remarks
 If either argument is nonnumeric, CHIDIST returns the #VALUE! error value.
 If x is negative, CHIDIST returns the #NUM! error value.
 If deg_freedom is not an integer, it is truncated.
 If deg_freedom < 1 or deg_freedom > 10^10, CHIDIST returns the #NUM! error value.
 CHIDIST is calculated as CHIDIST = P(X>x), where X is a χ^{2} random variable.
Example
The example may be easier to understand if you copy it to a blank worksheet.
How do I copy an example?
 Select the example in this article. If you are copying the example in Excel Online, copy and paste one cell at a time.
Important: Do not select the row or column headers.
Selecting an example from Help
 Press CTRL+C.
 Create a blank workbook or worksheet.
 In the worksheet, select cell A1, and press CTRL+V. If you are working in Excel Online, repeat copying and pasting for each cell in the example.
Important: For the example to work properly, you must paste it into cell A1 of the worksheet.
 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.
After you copy the example to a blank worksheet, you can adapt it to suit your needs.

A 
B 
Data 
Description 
18.307 
Value at which you want to evaluate the distribution 
10 
Degrees of freedom 
Formula 
Description (Result) 
=CHIDIST(A2,A3) 
Onetailed probability of the chisquared distribution, for the above terms (0.050001) 
