The interquartile range, often abbreviated IQR, is the difference between the 25th percentile (Q1) and the 75th percentile (Q3) in a dataset.

We often declare an observation to be an outlier in a dataset if it has a value 1.5 times greater than the IQR or 1.5 times less than the IQR.

This calculator uses this formula to automatically calculate the upper and lower outlier boundaries for a given dataset.

Simply enter the list of the comma-separated values for the dataset, then click the “Calculate” button:

**Dataset values:**

**Q1: 5.0000**

**Q3: 20.7500**

**Interquartile Range: 15.7500**

**Lower Outlier Boundary: -18.6250**

**Upper Outlier Boundary: 44.3750**