The average — formally the arithmetic mean — is the most common way to summarize a set of numbers with a single value. This calculator handles the arithmetic for you: paste in any list and get the mean, sum, count, minimum, maximum, and range at once.
How the average is calculated
The arithmetic mean is the sum of the included values divided by their count. Compensated summation retains small contributions during cancellation. Strict parsing rejects invalid tokens; the optional omission policy identifies them in the ledger. The weighted mean is Σ(wx)/Σw with a positive total weight. Exclusions are reversible, and mean, median, plot and exports use the same included dataset.
Average vs. median vs. mode
The average is only one way to describe the "center" of a data set. The median (the middle value when sorted) and the mode (the most frequent value) can tell a different story, especially when a few very large or very small numbers are pulling the average away from what's typical. If you need median or mode as well, use the Mean, Median & Mode Calculator.
When the average can mislead
A single outlier — one unusually large or small value — can shift the average significantly, even if the rest of the data looks nothing like it. Income and home-price data are classic examples: a few very high values pull the average well above what most people actually earn or pay. Checking the range alongside the average is a quick way to spot this: a wide range relative to the average is a signal to look more closely at the individual values, or to compute the median for comparison.