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
Choose the generator: RAND() for decimals, RANDBETWEEN(bottom, top) for whole numbers, RANDARRAY for a block.
Type the formula in the first cell and fill it down or across as far as you need.
Press F9 to redraw; every recalculation changes every random cell in the workbook.
To lock a result, select the cells, Ctrl+C, then Home ▸ Paste ▸ Values.
To shuffle an existing list, put =RAND() in a helper column, then Data ▸ Sort by that column and delete the helper.
For a decimal in a custom range, use =RAND()*(max-min)+min — for example =RAND()*(10-5)+5 for 5 to 10.
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. For “randomize numbers in excel”, 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 cells 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
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. Check the referenced cells, argument order and result type in your workbook. Start with the worked example before changing an input, then compare the changed result with the calculation you expected. An error value or a result of a different type is a reason to inspect the inputs and arguments.
In Google Sheets
Function availability: RANDARRAY: Excel 2021+; SORTBY: Excel 2021+. These are Microsoft's version markers; earlier perpetual releases do not include these functions. Check the actual product and update channel before using the formula. A marker does not establish an identical Web/Mac workflow or Google Sheets support. The aim was to get you unstuck fast and leave you a little more capable than a copy-paste would. The answer is at the top and the detail above shows why it holds — so the next time a colleague asks, you can answer without reaching for search. For “randomize numbers in excel”, keep the input cells and the result visible while you check the formula in Excel. Follow the worked example and change one input at a time. The steps explain the workbook calculation; this page does not run a live calculator for that task.
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.