The formula
How it works
Find the mean, median, mode and range of a list of numbers — the four everyday measures of a data set’s centre and spread. Type or paste your values and read all four at once.
FAQ
When should I use the median instead of the mean?
Use the median when a few unusually large or small values would distort the average — like house prices or incomes. The median, being the middle value, is not pulled by extremes the way the mean is.
Can a data set have more than one mode?
Yes. If two or more values tie for the most appearances, all of them are modes. If every value appears the same number of times, there is no mode at all.
How is the median calculated for an even number of values?
It is the average of the two middle values once the list is sorted — for example, 4, 6, 9, 11 has a median of (6 + 9) / 2 = 7.5.
Why is the mean sensitive to outliers but the median is not?
The mean adds every value into its total, so one extreme number pulls it up or down; the median only looks at position in the sorted order, so an outlier just becomes the new highest or lowest entry without shifting the middle.
What does a large range tell me?
A large range shows the data is spread widely between its smallest and largest values, though it only looks at those two extremes and says nothing about how the values in between are distributed.
Does the order I type the numbers in matter?
No — the calculator sorts the values internally before finding the median and range, so typing them in any order gives the same results.
How many numbers do I need for these statistics to be meaningful?
Mean, median and range can be computed from as few as two numbers, but with very small data sets they can be swayed heavily by a single value, so larger samples give a more reliable picture.
About the mean, median, mode and range calculator
This calculator finds the four most common summary statistics of a list of numbers: the mean, the median, the mode and the range. The first three each describe the “centre” of the data in a different way, while the range shows how spread out it is. Together they are the first things you learn in statistics and the quickest way to get a feel for a set of numbers.
How to use it
Type or paste your numbers, separated by commas, spaces or new lines. The calculator instantly shows the mean (the average), the median (the middle value when sorted), the mode (the most frequent value), and the range (largest minus smallest). For example, the numbers 3, 5, 7, 7, 9 and 12 have a mean of about 7.2, a median of 7, a mode of 7 and a range of 9. Non-numeric text is ignored.
The formula
The mean is the sum over the count, . The median is the middle value of the sorted list — or the average of the two middle values if there is an even number. The mode is whichever value occurs most often, and the range is simply the maximum minus the minimum. Each answers the question “what is a typical value?” — or, for the range, “how varied are the values?” — from a different angle.
Where it is used
These four measures appear throughout school maths, science and everyday reporting. The mean summarises test scores and averages; the median is preferred for incomes, house prices and reaction times where outliers skew the mean; the mode identifies the most popular choice or common value; and the range gives a quick sense of variability. Knowing when to use each is a core data-literacy skill.