The Excel QUARTILE.INC Function
The 1st, 2nd, 3rd or 4th quartile of a range of data is the value that 25%, 50%, 75% or 100% (respectively) of the data values fall within.
This is explained in more detail on the Wikipedia Quartile page
QUARTILE.INC & QUARTILE.EXC Functions
In Excel 2010, the new QUARTILE.INC and QUARTILE.EXC functions both find a requested quartile of a supplied data set.
The difference between these two functions is that the Quartile.Inc function bases its calculation on a percentile range of 0 to 1 inclusive, whereas the Quartile.Exc function bases its calculation on a percentile range of 0 to 1 exclusive.
The Excel QUARTILE.INC function returns a requested quartile of a supplied range of values, based on a percentile range of 0 to 1 (inclusive).
The function is new in Excel 2010 and so is not available in earlier versions of Excel. However, Quartile.Inc is simply a renamed version of the old Quartile function, that is available in earlier versions of Excel.
The format of the Quartile.Inc function is:
QUARTILE.INC( array, quart )
Where the function arguments are:
|array||-||The range of data values for which you want to calculate the specified quartile.|
|quart||-||An integer between 0 and 4, representing the required quartile.|
If the requested quartile falls between two of the values in the supplied array, Excel interpolates between these values to calculate the quartile value.
Note that the Quartile.Inc function is closely related to the Excel Percentile.Inc function in that:
- The 1st quartile is the same as the 25th percentile;
- The 2nd quartile is the same as the 50th percentile;
- The 3rd quartile is the same as the 75th percentile;
- The 4th quartile is the same as the 100th percentile (and is equal to the maximum value in the range).
Quartile.Inc Function Examples
The spreadsheets below show examples of the Excel Quartile.Inc function used to calculate the quartiles of the set of values 0 - 6 (stored in cells A1-A7 of the example spreadsheet).
|1||2||=QUARTILE.INC( A1:A7, 0 )|
|2||1||=QUARTILE.INC( A1:A7, 1 )|
|3||6||=QUARTILE.INC( A1:A7, 2 )|
|4||4||=QUARTILE.INC( A1:A7, 3 )|
|5||3||=QUARTILE.INC( A1:A7, 4 )|
Note that in the above examples:
- The 1st quartile (calculated in cell B2) falls half way between the values of 1 and 2. Therefore, Excel has interpolated the data, to produce the result 1.5;
- The 3rd quartile (calculated in cell B4) falls half way between the values of 4 and 5. Therefore Excel has interpolated the data, to produce the result, 4.5.
For further examples of the Excel Quartile.Inc function, see the Microsoft Office website
Quartile.Inc Function Errors
If you get an error from the Excel Quartile.Inc function this is likely to be one of the following:
Occurs if either:
- The supplied value of quart is is < 0 or > 4
- The supplied array is empty.
|#VALUE!||-||Occurs if the supplied value of quart cannot be interpreted as a numeric value.|