Average Calculator
Paste any list of numbers and get the mean, median, sum, spread and more.
Mean vs. median: which average to use
The mean adds everything and divides by the count; the median is the middle value when sorted. The mean is the everyday 'average', but a single outlier drags it around: one billionaire in a room makes the mean income meaningless while the median barely moves. For skewed data (incomes, house prices, response times), the median is usually the honest number.
Standard deviation in one sentence
It measures how spread out the values are around the mean; roughly, the typical distance from average. This calculator reports the sample standard deviation (divides by n-1), which is what you want when your numbers are a sample rather than the entire population.