by Svetlana Cheusheva, updated on
In this article, we'll discuss a few different formulas to randomize in Excel without repeating numbers. Also, we will show you a universal Random Generator that can produce a list of random numbers, dates, and strings with no repeats.
As you probably know, Microsoft Excel has several functions for generating random numbers such as RAND, RANDBETWEEN and RANDARRAY. However, there is no guarantee that the result of any function will be duplicate free.
This tutorial explains a few formulas for creating a list of unique random numbers. Please pay attention that some formulas only work in the latest version of Excel 365 and 2021 while others can be used in any version of Excel 2019, Excel 2016, Excel 2013 and earlier.
Only works in Excel 365 and Excel 2021 that support dynamic arrays.
If you have the latest Excel version, the easiest way for you to get a list of unique random numbers is to combine 3 new dynamic array functions: SORTBY, SEQUENCE and RANDARRAY:
Where n is the number of random values you want to get.
For example, to create a list of 5 random numbers, use 5 for n:
=SORTBY(SEQUENCE(5), RANDARRAY(5))
Enter the formula in the topmost cell, press the Enter key, and the results will spill automatically over the specified number of cells.
As you can see in the screenshot below, this formula actually sorts numbers from 1 to 5 in random order. If you need a classic random number generator with no repeats, then please check out other examples that follow below.
In the above formula, you only define how many rows to fill. All other arguments are left to their default values, meaning the list will start at 1 and will be incremented by 1. If you'd like a different first number and increment, then set your own values for the 3rd (start) and 4th (step) arguments of the SEQUENCE function.
For instance, to start at 100 and increment by 10, use this formula:
=SORTBY(SEQUENCE(5, , 100, 10), RANDARRAY(5))
How this formula works:
Working from the inside out, here's what the formula does:
Please keep in mind that this simple formula creates a list of non repeating random numbers with a predefined step. To bypass this limitation, use an advanced version of the formula described below.
Only works in Excel 365 and Excel 2021 that support dynamic arrays.
To generate random numbers in Excel without duplicates, use one of the below generic formulas.
Random integers:
Random decimals:
Where:
For example, to create a list of 5 random integers from 1 to 100 with no repeats, use this formula:
=INDEX(UNIQUE(RANDARRAY(5^2, 1, 1, 100, TRUE)), SEQUENCE(5))
To generate 5 unique random decimal numbers, put FALSE in the last argument of RANDARRAY or omit this argument:
=INDEX(UNIQUE(RANDARRAY(5^2, 1, 1, 100)), SEQUENCE(5))
How this formula works:
At first sight the formula may look a bit tricky, but upon a closer look its logic is very straightforward:
Note. On very large arrays, this formula may be a bit slow. For example, to get a list of 1,000 unique numbers as the final result, RANDARRAY would have to generate of array of 1,000,000 random numbers (1000^2) internally. In such situations, instead of raising to power, you can multiply n by, say, 10 or 20. Just keep in mind please that the smaller array is passed to the UNIQUE function (small relative to the desired number of unique random values), the bigger the chance that not all cells in the spill range will be filled with the results.
Only works in Excel 365 and Excel 2021 that support dynamic arrays.
To generate a range of random numbers with no repeats, you can use this formula:
Where:
As you may notice, the formula is basically the same as in the previous example. The only difference is the SEQUENCE function, which in this case defines both the number of rows and columns.
For instance, to fill a range of 10 rows and 3 columns with unique random numbers from 1 to 100, use this formula:
=INDEX(UNIQUE(RANDARRAY(30^2, 1, 1, 100)), SEQUENCE(10, 3))
And it will produce an array of random decimals without repeating numbers:
If you need whole numbers, then set the last argument of RANDARRAY to TRUE:
=INDEX(UNIQUE(RANDARRAY(30^2, 1, 1, 100, TRUE)), SEQUENCE(10,3))
As no version other than Excel 365 and 2021 supports dynamic arrays, none of the above solutions work in earlier versions of Excel. However, this does not mean there is no solution at all, you'll just have to perform a few more steps:
Be sure to generate more values than you actually need because some will be duplicates and you'll delete them later.
For this example, we are creating a list of 10 random integers between 1 and 20 by using the below formula:
=RANDBETWEEN(1,20)
To enter the formula in multiple cells in one go, select all the cells (A2:A15 in our example), type the formula in the formula bar and press Ctrl + Enter. Or you can enter the formula in the first cell as usual, and then drag it down to as many cells as needed.
Anyway, the result will look something like this:
As you may notice, we've entered the formula in 14 cells, though eventually we only need 10 unique random numbers.
To make sure you've done it right, select any number and look at the formula bar. It should now display a value, not a formula:
Done! All duplicates are gone, and you can now delete the excess numbers.
Tip. Instead of Excel's built-in tool, you can use our advanced Duplicate Remover for Excel.
All of the randomizing functions in Excel including RAND, RANDBETWEEN and RANDARRAY are volatile, meaning they recalculate every time the spreadsheet is changed. As the result, new random values are produced with every change. To prevent generating new numbers automatically, use the Paste Special > Values feature to replace formulas with static values. Here's how:
For the detailed steps, please see How to change formulas to values in Excel.
The users of our Ultimate Suite do not really need any of the above solutions because they already have a universal Random Generator in their Excel. This tool can easily produce a list of non-repeating integers, decimals numbers, dates, and unique passwords. Here's how:
That's it! The selected range gets filled with non-repeating random numbers at once:
If you are curious to try this tool and explore other fascinating features included with our Ultimate Suite, you are welcome to download a trial version.
That's how to randomize numbers in Excel without duplicates. I thank you for reading and hope to see you on our blog next week!
Generate unique random numbers in Excel (.xlsx file)
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