Average Calculator

How do you calculate the average? Add all values and divide by how many there are: the average (arithmetic mean) of 4, 8, 15, 16, 23 and 42 is 108 ÷ 6 = 18. This calculator does that for any list you paste — with the median and sum alongside, because the mean alone can mislead.

The mean's weakness is outliers: one enormous value drags it away from "typical." Median — the middle value when sorted — resists that pull, which is why house prices and incomes are reported as medians. When mean and median diverge sharply, the data is skewed and quoting only the mean is (accidentally or otherwise) spin.

Paste or type your numbers — separated by spaces, commas or new lines — and read the mean, median, sum and count instantly, updating as you edit.

Everyday jobs: averaging grades or test scores (and answering "what do I need on the final" by experimenting — add the hypothetical score and watch the mean move), averaging monthly expenses or sales for budgeting, computing average response or delivery times from a log, and checking a reported "average" against the median to see whether outliers are doing the talking.

The weighted-average caveat: when items count unequally (course credits, portfolio positions), the plain mean is wrong — multiply each value by its weight, sum, and divide by total weight. For simple equal-weight lists, which is most lists, this calculator is the tool.