1. Home
  2. Statistics Calculators
  3. Outlier Calculator

Outlier Calculator

The outlier calculator is designed to identify outliers in a given dataset using various statistical techniques. Such as Z-score and Interquartile Range (IQR).

Numbers with comma (,) or space separator.

Outliers:

First Quartile:
Third Quartile:
Interquartile Range:
Median:
Lower Fence:
Upper Fence:
Minimum:
Maximum:

How to Use the Outlier Calculator?

  1. First, enter the set of numbers with comma or space delimiters. Example: 10, 23, 42 or 10 23 42.
  2. After entering the data, press the 'Calculate' button.
  3. The tool immediately identifies the outliers from the given dataset and displays them in the result section. If no outliers are detected in a dataset, it will show 'None'.
  4. The calculator also returns the first quartile, third quartile, IQR, median, lower and upper fences, minimum, and maximum results.

How to Calculate Outliers?

There are several methods to determine the outliers, but the most common method is using the Interquartile Range (IQR). This calculator also uses this method to identify outliers. Let's know how it works with an example.

Example:

Find the outliers for the dataset: [12, 23, 33, 52, 32, 99].

Solution:

Step 1: Arrange the dataset in ascending order.

[12, 23, 32, 33, 52, 99]

Step 2: Find the first and third quartiles.

First quartile (Q1) = 23

Third quartile (Q3) = 52

Step 3: Compute the interquartile range (IQR).

IQR = Q3 - Q1 = 52 - 23 = 29

Step 4: Determine the lower and upper fences for outliers.

Lower Fence = Q1 - (1.5 × IQR) = -20.5

Upper Fence = Q3 + (1.5 × IQR) = 95.5

Step 5: Find the numbers in a dataset that are greater or lesser than the fences.

Outlier(s) = 99 (It's greater than 95.5).

Related Calculators