Average Calculator

Mean, median and mode in one place

"Average" is ambiguous — it usually means the arithmetic mean, but the median and the mode are averages too, and they answer different questions. This calculator reports all three at once so you can see when they disagree.

• Mean — add every value, divide by how many there are. Sensitive to outliers.
• Median — sort the list, take the middle value. Barely moves when one value is extreme.
• Mode — the value that appears most often. Useful for categories and repeated readings.

When the mean misleads

Take five salaries: 32,000, 35,000, 38,000, 41,000 and 400,000. The mean is 109,200 — a figure nobody in the group earns. The median is 38,000, which describes the group far better.

This is why income, house prices and response times are almost always reported as medians. If your mean and median are far apart, one or two values are doing the talking, and you should say so when you present the number.

Range and standard deviation

The range is simply the largest value minus the smallest — a quick sense of spread, but it only looks at two numbers. Standard deviation measures how far values sit from the mean on average, so it uses the whole list. A small standard deviation means the values cluster tightly; a large one means they scatter.

Input formats

Paste numbers separated by commas, spaces or line breaks — all three work, and you can mix them. Non-numeric text is ignored, so pasting a column out of a spreadsheet usually works without cleaning it up first.