Five Number Summary Calculator

A five-number summary describes a data set with five values: the minimum, the first quartile (Q1), the median (Q2), the third quartile (Q3), and the maximum. Together they show the center, spread, and shape of the data. They are exactly the five values a box-and-whisker plot draws.

It sorts your numbers, then finds the median to split the data into a lower and an upper half. Q1 is the median of the lower half and Q3 is the median of the upper half. This is the Tukey exclusive method, so for an odd count the overall median is left out of both halves. It matches the site's interquartile range calculator.

The interquartile range (IQR) is Q3 minus Q1, the spread of the middle 50 percent of your data. The range is the maximum minus the minimum, the full spread from lowest to highest value. The IQR is more resistant to outliers than the range because it ignores the extreme tails.

You need at least 4 values so each half has at least one number and Q1 and Q3 are defined. The calculator accepts decimals and negative numbers, and you can separate values with commas, spaces, or new lines. It sorts the data for you, so the order you type does not matter.

The calculator applies the standard Tukey rule using fences at Q1 minus 1.5 times the IQR and Q3 plus 1.5 times the IQR. Any value below the lower fence or above the upper fence is listed as an outlier. These fences also mark where a box plot ends its whiskers.

Not always. There are several accepted quartile conventions. This tool uses the Tukey exclusive method, which matches the QUARTILE.EXC function in Excel for the median split but can differ from QUARTILE.INC, from the TI-83 or TI-84, and from some software defaults. The minimum, median, maximum, and range are the same across methods.