how to find the iqr

Interquartile range aka IQR is the middle 50% of a dataset. With the help of either of the statistical functions Percentile or Quartile, you can find this measure of statistical dispersion. Let's see how to find the Interquartile Range in Google Sheets.

The Quartile function can divide your dataset into four equal parts. They are 0%-25%, 25%-50%, 50%-75% and 75%-100%.

When you divide a dataset into 4 equal parts there would be 3 cut marks. They are Q1 (25%), Q2 (50%) and Q3 (75%).

The interquartile range is the difference between Q3 and Q1 that means Q3-Q1. You can also say the difference between 25th and 75th percentiles. Let me show you how to find the interquartile range in Google Sheets.

Formulas to Find Interquartile Range in Google Sheets

For manually finding the IQR, you must order your dataset from the smallest to the largest number (ascending order). But in Spreadsheet applications, it's not necessary to keep the numbers in any particular order.

Sample Data:

Find Interquartile (IQR) Range in Google Sheets

Below I am going to provide two different formulas to find the IQR in Docs Sheets. As mentioned above, one is using the Quartile function and the other one is using the Percentile function.

Find IQR Using Quartile Function in Sheets

To find the interquartile range in Google Sheets, first, you should find the Q1 and Q3 using the following formulas.

Q1 in Cell C2:

Enter the below Quartile formula in cell C2 to get the Q1.

          =Quartile(A2:A14,1)

Q3 in Cell D2:

Similarly above you can get the Q3 in cell D2.

          =Quartile(A2:A14,3)

IQR in cell E2:

          =D2-C2

Do we need to use all the above three formulas to find the IQR in Docs Sheets?

Nope! You can simply use the below combined formula for this purpose.

          =Quartile(A2:A14,3)-Quartile(A2:A14,1)

Find IQR Using Percentile Function in Sheets

Since we can find the Q1 and Q3 using the Percentile function, we can use this function also for finding IQR in Google Sheets.

Replace the Quartile formulas in cell C2 and D2 with the following Percentile formulas.

Percentile Formula in C2:

          =Percentile(A2:A14,25%)

Percentile Formula in D2:

          =Percentile(A2:A14,75%)

You can keep the same formula in cell E2, i.e., =D2-C2. Here also, you can use a combined Percentile formula to calculate the IQR in Sheets. Here is that formula.

          =Percentile(A2:A14,75%)-Percentile(A2:A14,25%)