In Excel: use =RANDBETWEEN(1,100) for a whole number in a range, =RAND() for a decimal between 0 and 1, or =RANDARRAY(10,1,1,100,TRUE) in Microsoft 365 for a whole block at once.
On this page7
Seed: 20260101
Need it as an auditable file?
Ships inside the linked template — formula-driven, unlocked, audit-ready.
What this does
Excel has three generators. RAND() returns a decimal ≥0 and <1. RANDBETWEEN(bottom, top) returns a whole number in an inclusive range. RANDARRAY(rows, columns, min, max, whole_number) spills a whole grid in Microsoft 365. All three are volatile: they produce a new value on every recalculation, every edit and every file open. To freeze a draw, copy the cells and Paste Special ▸ Values. To shuffle a list rather than generate numbers, add a =RAND() helper column and sort by it — or use =SORTBY(A2:A50, RANDARRAY(49)) in Microsoft 365. The same idea underpins a lot of everyday Excel work, so the few minutes spent getting it right here pay back across every sheet you build afterwards. Treat it as a pattern, not a one-off, and it stops being something you look up and starts being something you reach for. The difference between a quick fix and a sheet you can trust is the extra minute you spend validating “assign random numbers 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 calculation you can defend to a CFO or an auditor, but the practical win is that someone else can open the file and understand what happened without asking you.
A worked example
Ten random whole numbers from 1 to 100: enter =RANDBETWEEN(1,100) in A2 and fill down to A11. Press F9 and all ten change. To keep one particular draw, select A2:A11, Ctrl+C, then Home ▸ Paste ▸ Values. To pick 5 winners from a list of names in A2:A200 without repeats: =INDEX($A$2:$A$200, RANK(B2, $B$2:$B$200)) beside a =RAND() column, or simply =SORTBY(A2:A200, RANDARRAY(199)) and take the top 5. Random numbers drive sample selection, prize draws, test data and Monte Carlo models — and the two things that catch people out, volatility and repeated values, are both easy to control once you know they are there. If there is any chance you will reuse this, drop it into a small template tab right now: a labelled input area on the left and the formula beside it, checked once against the tool above. Next time the same question comes up, the answer is a single paste away instead of a rebuild from memory.
In Google Sheets
Some functions on this page are newer additions to Excel: they are in current Microsoft 365 and Excel for the web, while older perpetual Excel versions return #NAME?. Google Sheets maintains its own function list, so confirm each function exists there before relying on the same formula. 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. Here is the takeaway for “assign random numbers in excel”: copy the answer if you are busy, but if you have a spare few minutes, rebuild the example in Excel yourself with the tool above open beside it. That single pass — type it, run it, watch the result move when you change an input — is what turns a formula you found into a technique you trust. Keep your inputs labelled and referenced, never hard-coded, and the same sheet stays correct and auditable as it grows. Done that way, you will not need to look this up again, and you will be the person others ask.
Common mistakes
- Forgetting the functions are volatile, so the "random sample" in a report changes the next time anyone opens the file.
- Assuming
RANDBETWEENgives unique values — it draws with replacement, so duplicates are expected. Use aRANDhelper column plusRANK, orSORTBYwithRANDARRAY, when you need distinct picks. - Building a big sheet on thousands of volatile cells, which makes every keystroke recalculate the workbook.
- Treating Excel's generator as cryptographically secure; it is fine for sampling and demos, not for keys or passwords.
- Referencing a random cell from another formula and wondering why the two disagree — they were evaluated on different recalculations.
Frequently asked questions
How do I generate a random number in Excel?
=RANDBETWEEN(1,100) gives a whole number from 1 to 100 inclusive. =RAND() gives a decimal between 0 and 1. Both redraw on every recalculation.
How do I stop random numbers from changing?
Select the cells, copy them, then Home ▸ Paste ▸ Values. That replaces the volatile formulas with the numbers they last produced.
How do I randomise a list of names?
Add =RAND() in a helper column beside the list, sort the list by that column, then delete the helper. In Microsoft 365, =SORTBY(A2:A50, RANDARRAY(49)) does it in one formula.
How do I get random numbers without duplicates?
Generate a =RAND() value per row and rank them: =INDEX($A$2:$A$200, RANK(B2,$B$2:$B$200)). Ranking a set of distinct random decimals yields distinct picks, unlike RANDBETWEEN.
Other ways people ask this
People reach this page typing “excel assign random number” and “how to assign random numbers in excel”, among other phrasings; whichever wording you used, the fix above is the one you want.
Why do people search for this in so many different ways?
Because the same task has many names. “excel assign random number”, “how to assign random numbers in excel” all point at the one operation explained on this page, which is why they all lead here.