Enter the average value of Q1 and Q3, and the interquartile range into the calculator to determine the low and high outliers.

## Outlier Formula

The following equation can be used to calculate the values of the outliers.

L = Q1 – (1.5* IQR)

H = Q3 + (1.5*IQR)

- Where L is the lower outlier
- H is the higher outlier
- Q1 and Q3 are the average values of those quartiles
- IQR is the interquartile range

## Outlier Definition

An outlier is defined as the extreme values of a set of data that vary the most from the mean or norm.

## FAQ

**What is an outlier?**

An outlier is a term used in statistics to describe extreme values that vary from the norm of a data set. In other words, the highest and lowest values of a data set that sit apart from the rest.

**What causes outliers?**

Outliers occur either by chance or by measurement error.

**How many outliers are there?**

There can be any number of outliers, but often times the outliers can be the sample maximum and minimums as the formula above calculates.