In more detail
To find the median, sort the values and take the one in the middle. With an even number of values, take the mean of the two middle ones. Unlike the Mean, median and mode (mean), the median depends only on the order of the values, not on how large the extreme ones are, so a few very high or very low values barely move it.
Why it matters
The median describes a typical value in skewed data such as incomes, house prices, waiting times and file sizes, where a handful of huge values drag the mean upward. Reports that give both a mean and a median show at a glance whether the data is skewed: a mean far above the median means a long tail of large values. For spread, the Standard deviation is the usual companion to the mean.
Example
For the values 32,000, 35,000, 35,000, 38,000, 41,000, 45,000, 52,000 and 250,000 the median is the mean of 38,000 and 41,000, which is 39,500. The mean is 66,000, pulled up by the single value of 250,000. Calculate both with the Mean, Median, Mode & Range Calculator.
Common confusion
The median is not the same as the mean or the mode. It is also not the 'middle' of the range: it is the middle of the sorted values, so for 1, 2 and 100 the median is 2 even though the midpoint of the range is 50.5.