Excel Function VAR

What this does

Variance is the average squared distance of each value from the mean — the raw measure of spread that standard deviation is built on. Because it squares the differences, its units are squared too (euros², points²), which is why standard deviation, its square root, is usually the figure people quote. Variance still matters wherever the maths needs the un-rooted quantity, such as combining the spread of independent sources. Keep the inputs visible and clearly labelled and the whole thing stays auditable — anyone who opens the file later, including you, can see at a glance exactly what feeds the result and change one assumption without hunting through the formula. For “excel function var”, the reliable version is a short checking loop, not just the first command that appears to work. Run it on a deliberately small range first, watch how the affected formula change, and only then apply the same setup to the full sheet. 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. That is what makes a calculation you can defend to a CFO or an auditor useful in real work: repeatable, auditable, and not dependent on memory or luck.

A worked example

For 12, 15, 9, 21, 17, 14 (mean 14.67), =VAR.S(A1:A6) returns about 17.07. Take its square root and you get the standard deviation, ≈4.13. The tool above shows both so you can see the relationship: variance is the engine, standard deviation is the readable dashboard. Variance underpins portfolio theory, ANOVA, and any model that has to add up uncertainty from several sources. When the next step is more maths rather than a human-readable report, variance is the quantity you keep. 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

Everything above works in Google Sheets too. Excel and Sheets share the formula syntax used here; only the surrounding menus are arranged differently. That portability is deliberate — learn it once and it follows you between the two tools and across Windows and Mac. Nothing on this page is behind a login: the tool runs entirely in your browser, the formula is shown in full with one-click copy, and the steps work the same on Windows and Mac. That is the whole promise here — the exact answer, a way to prove it on your own numbers, and just enough context to make it stick. If you take one thing from this page on “excel function var”, make it the habit rather than the keystrokes: set the problem up with labelled inputs, reference those cells, and let Excel do the recomputing. Bookmark the page for the syntax, but do the example once in a blank sheet and check it against the tool above — five minutes of hands-on practice fixes the method in memory far better than re-reading, and it surfaces the small snags while they are still harmless. After that the technique is genuinely yours: faster than searching for it again, and reliable enough to drop into work that other people depend on.

Common mistakes

• Reporting variance where readers expect standard deviation — the squared units mislead.
• Choosing VAR.P for a sample, which understates the true spread.
• Including non-numeric cells in the range.
• Forgetting that adding a constant to every value leaves variance unchanged, while scaling multiplies it by the square.

Frequently asked questions