Average Calculator
100% private — runs on your device, never uploaded. Works offline once loaded.
Paste or type a list of numbers separated by commas, spaces or new lines to get the mean, median, mode, range, sum, count and sample standard deviation at once.
Mean, median and mode explained
Average is a loose word, so this tool reports all three common measures of the centre of a data set. The mean is the arithmetic average: add every value and divide by how many there are. The median is the middle value once the numbers are sorted (or the average of the two middle values when the count is even). The mode is the value that appears most often — a set can have one mode, several, or none if every value is unique.
These three can differ a lot, and that difference is informative. In a symmetric set they cluster together, but when a few very large or very small values pull the mean away from the bulk of the data, the median often gives a fairer sense of the typical value. Seeing all three side by side helps you choose the right one for your situation.
Spread: range and standard deviation
Knowing the centre is only half the story; you also want to know how spread out the numbers are. The range is the simplest measure — the largest value minus the smallest — and it is quick but sensitive to a single outlier. The tool also shows the minimum and maximum so you can see the endpoints directly.
For a fuller picture it computes the sample standard deviation, which measures the typical distance of each value from the mean. It uses the n−1 (Bessel's) denominator, the correct choice when your numbers are a sample drawn from a larger population rather than the entire population. A small standard deviation means the values are tightly clustered; a large one means they are widely scattered.
- Mean = sum ÷ count
- Median = middle value of the sorted list
- Range = maximum − minimum
- Sample standard deviation uses division by n − 1
How to enter your data
You can paste numbers straight from a spreadsheet column, a report or a text file. Separators are flexible: commas, spaces, semicolons and line breaks all work, and you can mix them in the same list. Empty entries and anything that is not a number are simply skipped, so stray labels will not break the calculation.
Because the results recalculate as you type, the tool is well suited to quick, exploratory work — checking a set of test scores, tallying expenses, summarising survey responses or sanity-checking a column before you commit to a formula. For very large lists, all the heavy lifting still happens locally in your browser, so there is no upload step and no waiting on a server.
Frequently asked questions
What separators can I use between numbers?
Commas, spaces, semicolons and new lines, in any combination. The parser splits on all of them and ignores empty pieces.
What happens to non-numeric text?
It is ignored. Only values that parse as numbers are included, so pasted headings or labels won't affect the results.
Which standard deviation is calculated?
The sample standard deviation, using the n − 1 denominator. This is the appropriate choice when your data is a sample of a larger population.
Can there be more than one mode?
Yes. If several values tie for the highest frequency, all of them are shown. If every value occurs only once, the mode is reported as none.
How is the median found for an even count?
The numbers are sorted and the two middle values are averaged. For an odd count, the single middle value is used.
Is my data private?
Yes. All statistics are computed in your browser, so the numbers you paste are never uploaded or stored.
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