How to use the RANDBETWEEN function
What is the RANDBETWEEN function?
Returns a random whole number between the numbers you specify. This function is volatile meaning a new random number is created every time the worksheet is calculated.
What is random?
Each outcome of a random process cannot be predicted with certainty before it occurs. It is unpredictable.
Is the RANDBETWEEN function random?
No, it is pseudo-random. The generated value is not truly random.
What is pseudo-random?
True randomness doesn't really exist in software like Excel. The random values only look random, but are not actually random since they come from an algorithm.
What is volatile?
The RANDBETWEEN function is volatile, which means that every time the worksheet recalculates, the function runs again and a new random-looking number is returned.
What is the effect of volatile functions?
Having a lot of volatile random functions like RANDBETWEEN on your worksheet can slow down calculation, because they keep recalculating even when their inputs don't change.
When is the worksheet calculated?
Cells containing non volatile functions are only calculated once or until you force a recalculation, however, volatile functions are recalculated each time you type in a cell and press enter.
Can you stop recalculating a worksheet?
Yes, you can change a setting to manual recalculations.
- Go to tab "Formulas".
- Press with left mouse button on the "Calculation Options" button, a popup menu appears.
- Press with mouse on "Manual".
This stops the automatic recalculations.
How to force a recalculation?
Pressing F9 key will recalculate or refresh all the formulas and values in every worksheet of every workbook you have open.
Pressing Shift+F9 will only recalculate the formulas and values on the single worksheet you're currently viewing or active.
Pressing Ctrl+Alt+F9 is the quickest way to force a full recalculation of absolutely everything in all open workbooks, even if nothing has changed. It ignores whether changes were made or not and completely recomputes.
Are there more volatile functions in Excel?
Yes. OFFSET, TODAY, NOW among others.
| Function | Syntax | Description |
|---|---|---|
| OFFSET | OFFSET(reference, rows, cols) | Returns a cell offset from a reference cell. |
| TODAY | TODAY() | Returns the current date. |
| NOW | NOW() | Returns current date and time. |
| RANDARRAY | RANDARRAY([rows], [columns], [min], [max], [whole_number]) | Returns an array with random numbers. |
| RANDBETWEEN | RANDBETWEEN(bottom, top) | Returns a random whole number between bottom and top |
Note, that conditional formatting is extremely volatile or super-volatile meaning it is recalculated as you scroll through a worksheet.
What other functions return random values?
| Excel Function | Syntax | Description |
|---|---|---|
| RAND() | RAND() | Returns a random decimal number between 0 and 1 |
| RANDBETWEEN | RANDBETWEEN(bottom, top) | Returns a random whole number between bottom and top |
| RANDARRAY | RANDARRAY([rows], [columns], [min], [max], [whole_number]) | Returns an array with random numbers. |
Formula in cell D3:
Excel Function Syntax
RANDBETWEEN(bottom, top)
Arguments
| bottom | Required. The start number of the range you want to create a random number from. |
| top | Required. The end number of the range you want to create a random number from. |
Comments
Press F9 to calculate new random numbers. Use this function with care, it may slow down your workbook considerably if used extensively. This is the case with all volatile functions.
'RANDBETWEEN' function examples
This article demonstrates a formula that distributes given text strings randomly across records in any given day meaning they may […]
This article describes how to create a random playlist based on a given number of teams using an array formula. […]
Mark G asks: 1 - I see you could change the formula to have the experssion COUNTIF($C$1:C1, $E$2:$E$5)<5 changed so […]
Functions in 'Math and trigonometry' category
The RANDBETWEEN function function is one of many functions in the 'Math and trigonometry' category.
How to comment
How to add a formula to your comment
<code>Insert your formula here.</code>
Convert less than and larger than signs
Use html character entities instead of less than and larger than signs.
< becomes < and > becomes >
How to add VBA code to your comment
[vb 1="vbnet" language=","]
Put your VBA code here.
[/vb]
How to add a picture to your comment:
Upload picture to postimage.org or imgur
Paste image link to your comment.
Contact Oscar
You can contact me through this contact form