This quartile calculator finds the first quartile (lower), second quartile (median) and third quartile (upper) of a data set and is designed for helping in statistics calculations. You can read more about it below the tool.

## What is a quartile?

In statistics, a quartile is one of three points that divide a specific set of data into 4 equal groups, each group representing 1/4 part of the distributed sampled population.

The 3 types of quartiles are:

- first one (Q1) which is also called the lower quartile is equal to the data at the 25^{th} percentile of the given set;

- second one (Q2) which is also known as the median;

- third one which is also referred to as upper quartile is equal to the data at the 75^{th} percentile of the given set.

## How does this quartile calculator work?

This quartile calculator uses McCabe's formula that does not take account of the median of the data set when computing the 1^{st} and the 3^{rd} quartiles.

Practically the 1^{st} quartile is the median for the data set that contains all the values at the left of the 2^{nd} quartile median, while the 3^{rd} quartile is the median of the data set that contains all the values at the right of the 2^{nd} quartile median.

As explained within instruction the number should be separated by commas, space or break line. For instance this data set: 1,2,3,4,5,6,7,8,9,10 and its results:

■ 1^{st} quartile (lower quartile) = 3.25

■ 2^{st} quartile (median) = 5.5

■ 3^{st} quartile (upper quartile) = 7.75