Quartile

In descriptive statistics, a quartile is any of the three values which divide the sorted data set into four equal parts, so that each part represents 1/4th of the sample or population.

Thus:

• first quartile = lower quartile = cuts off lowest 25% of data = 25th percentile
• second quartile = median = cuts data set in half = 50th percentile
• third quartile = upper quartile = cuts off highest 25% of data, or lowest 75% = 75th percentile

The difference between the upper and lower quartiles is called the interquartile range.

Calculating quartiles

See Quantile for methods. The quartile is calculated as the 4-quantile.

See also

• Interquartile range
• Quantile
• Percentile
• Summary statistics

External links

• Quartiles – an example how to calculate it