In Excel: use =SKEW(range) to measure asymmetry — positive means a long right tail — and =KURT(range) to measure how heavy the tails are.
Syntax
Arguments
| Argument | Description | |
|---|---|---|
number1 | required | The first value or range. At least three values are needed for SKEW, four for KURT. |
number2, ... | optional | Further values or ranges. |
Related functions
n = 7 · Sum = 103.00 · Min = 9.00 · Max = 21.00
7 values
What this does
SKEW measures how lopsided a distribution is. Zero means symmetric, positive means a long right tail (a few very large values, typical of income and response times), negative means a long left tail. KURT measures tail weight relative to a normal distribution, where positive means more extreme outliers than normal. Their practical value is as a check before applying any method that assumes normality: a skew beyond roughly ±1 says the mean is a poor summary and the median should lead instead. SKEW needs at least three values, KURT at least four. Most people learn this as a sequence of clicks and forget it by next week; learning it as a pattern instead is what lets you apply it to the next, slightly different version of the problem without starting from scratch. That is the difference this page is trying to make. The difference between a quick fix and a sheet you can trust is the extra minute you spend validating “find skewness in excel”. Start on a copy or a tiny sample, keep the affected cells visible, and compare the result with the tool above before you touch the real workbook. When a formula is involved, keep the inputs labelled beside it, reference cells instead of typing values, and apply number formatting only after the result checks out. The point is a data step that keeps your analysis trustworthy, but the practical win is that someone else can open the file and understand what happened without asking you.
A worked example
Testing whether a mean is representative: =SKEW(B2:B500) returning 1.8 says the data has a long right tail and the median is the honest headline. Confirming with the two summaries: a large gap between =AVERAGE(B2:B500) and =MEDIAN(B2:B500) tells the same story. =KURT(B2:B500) above 3 warns of more extreme outliers than a normal distribution would produce. SKEW answers "is the mean lying to me", which is the question that should precede every reported average. A practical tip before you scale it up: build it once on a small block of test data, confirm the number against the tool on this page, and only then point it at your real sheet. That one habit catches almost every mistake while it is still cheap to fix, long before a wrong figure reaches a report or a colleague.
In Google Sheets
Google Sheets handles this almost identically to Excel. The formula syntax above is the same, and the menu lives under a slightly different label rather than a ribbon tab. Use the platform toggle at the top of the page to switch every keyboard shortcut between Windows and Mac, and expect at most cosmetic differences in naming. Keep this page bookmarked for the next time the same question comes up. Better still, rebuild the example once in your own sheet — doing it yourself, with the tool above to check against, is what turns a copied formula into a technique you own. The short version of “find skewness in excel”: the answer is at the top of this page, the tool proves it on your own numbers, and the sections above explain why it holds so the next variation does not stump you. Excel rewards people who reference cells instead of typing values and who keep inputs separate from formulas, because that is what makes a result you can audit months later. Build it once, deliberately, with the live tool as a check, and you convert a one-off lookup into a reusable skill — which is the whole point of learning the why and not just the what.
Common mistakes
- Reporting a mean on data with a skew beyond ±1, which describes almost nobody in the dataset.
- Running them on fewer than three or four values, which returns
#DIV/0!. - Treating a skew near zero as proof of normality; it rules out one departure, not all of them.
Frequently asked questions
What does a positive skew mean?
A long right tail — a few unusually large values pulling the mean above the median. Income and response times behave this way.
When should I use the median instead of the mean?
Whenever the skew is materially non-zero, roughly beyond ±1. The mean stops describing a typical case.
What does KURT tell me?
How heavy the tails are compared with a normal distribution. Positive means more extreme outliers than normal.