5 Ways IQR Excel

Introduction to IQR in Excel

Interquartile range (IQR) is a measure of the spread or dispersion of a dataset. It is calculated as the difference between the 75th percentile (Q3) and the 25th percentile (Q1) of the data. IQR is a useful tool for identifying outliers and understanding the distribution of data. In Excel, you can calculate IQR using various methods. Here are five ways to calculate IQR in Excel.

Method 1: Using the QUARTILE Function

The QUARTILE function in Excel calculates the specified quartile of a dataset. You can use this function to calculate Q1 and Q3, and then subtract Q1 from Q3 to get the IQR. The syntax for the QUARTILE function is QUARTILE(array, quart) where array is the range of data and quart is the quartile number (1 for Q1, 3 for Q3).

💡 Note: Make sure to enter the quartile number as 1 or 3, not as a percentage (0.25 or 0.75).

For example, if your data is in the range A1:A10, you can calculate IQR as follows: =QUARTILE(A1:A10, 3) - QUARTILE(A1:A10, 1)

Method 2: Using the PERCENTRANK Function

The PERCENTRANK function in Excel calculates the percentage rank of a value within a dataset. You can use this function to calculate the 25th and 75th percentiles, and then subtract the 25th percentile from the 75th percentile to get the IQR. The syntax for the PERCENTRANK function is PERCENTRANK(array, x) where array is the range of data and x is the value for which you want to calculate the percentage rank.

For example, if your data is in the range A1:A10, you can calculate IQR as follows: =PERCENTRANK.INC(A1:A10, 0.75) - PERCENTRANK.INC(A1:A10, 0.25)

Method 3: Using the SMALL and LARGE Functions

The SMALL and LARGE functions in Excel return the nth smallest or largest value in a dataset. You can use these functions to calculate Q1 and Q3, and then subtract Q1 from Q3 to get the IQR. The syntax for the SMALL and LARGE functions is SMALL(array, n) and LARGE(array, n) respectively, where array is the range of data and n is the position of the value you want to return.

For example, if your data is in the range A1:A10, you can calculate IQR as follows: =LARGE(A1:A10, 3) - SMALL(A1:A10, 3)

Method 4: Using the Excel Formula

You can also calculate IQR using a simple Excel formula: =(MAXIFS(A1:A10, A1:A10, “>=”&PERCENTRANK.INC(A1:A10, 0.25)) - MINIFS(A1:A10, A1:A10, “<=”&PERCENTRANK.INC(A1:A10, 0.75)))

This formula uses the MAXIFS and MINIFS functions to find the maximum and minimum values in the dataset that are greater than or equal to Q1 and less than or equal to Q3 respectively.

Method 5: Using the IQR Formula in Excel

If you are using Excel 2019 or later, you can use the IQR formula to calculate the interquartile range directly. The syntax for the IQR formula is IQR(array) where array is the range of data.

For example, if your data is in the range A1:A10, you can calculate IQR as follows: =IQR(A1:A10)

Method	Formula
QUARTILE Function	=QUARTILE(A1:A10, 3) - QUARTILE(A1:A10, 1)
PERCENTRANK Function	=PERCENTRANK.INC(A1:A10, 0.75) - PERCENTRANK.INC(A1:A10, 0.25)
SMALL and LARGE Functions	=LARGE(A1:A10, 3) - SMALL(A1:A10, 3)
Excel Formula	=(MAXIFS(A1:A10, A1:A10, ">="&PERCENTRANK.INC(A1:A10, 0.25)) - MINIFS(A1:A10, A1:A10, "<="&PERCENTRANK.INC(A1:A10, 0.75)))
IQR Formula	=IQR(A1:A10)

In summary, there are several ways to calculate IQR in Excel, including using the QUARTILE function, PERCENTRANK function, SMALL and LARGE functions, Excel formula, and IQR formula. Each method has its own advantages and disadvantages, and the choice of method depends on the specific needs of the user.