The interquartile range is a measure of how disbursed your data is around a mean. It’s normally used in conjunction with the mean and median of a data set. There are several ways to find an interquartile range (the easiest of which is probably our interquartile range calculator). However, you can also calculate the IQR in Excel 2007.

Step 1: Enter your data into an Excel column. For example, place your data in cells A2 to A10.
Step 2: Click a blank cell (for example, click cell B2) and then type =QUARTILE(A2:A10,1). You’ll need to replace A2:A10 with the actual values from your data set. The “1″ in this equation (A2:A10,1) represents the first quartile.

Step 3: Click a second blank cell (for example, click cell B3) and then type =QUARTILE(A2:A10,3). Replace A2:A10 with the actual values from your data set. The “3″ in this equation (A2:A10,1) represents the third quartile.
Step 4: Click a third blank cell (for example, click cell B4) and then type =B3-B2. If your quartile functions from Step 2 and 3 are in different locations, change the cell references.
That’s it!