How to Generate Random Number in a Range with Excel VBA

Not only in Excel VBA but also while working with almost all the programming languages, we often need to generate one or more random number (s) in between a range. In this article, I’ll show you how you can generate random numbers in a range with examples including both repetition and not-repetition.


Generate a Random Number in a Range with Excel VBA (Quick View)

Sub Random_Numbers_with_Rnd()

Bottom = 11
Top = 20
Random_Number = Application.WorksheetFunction.RandBetween(Bottom, Top)

End Sub

VBA Code to Generate Random Number in a Range in Excel


Download Practice Workbook

Download this practice workbook to exercise while you are reading this article.


2 Methods to Generate Random Number in a Range with Excel VBA

There are 2 methods available to generate a random number in a range with Excel VBA.

1. Generate Random Number in a Range with the Excel RandBetween Function in VBA

First of all, we’ll generate random numbers within a range using the RandBetween function of Excel in VBA.

The syntax of the RandBetween function is very simple.

=RANDBETWEEN (bottom, top)

It takes two number arguments called bottom and top and generates a random number between them, including them.

Therefore, to generate a random number between 1 and 100, the VBA code will be:

⧭ VBA Code:

Sub Random_Numbers_with_RandBetween()

Bottom = 11
Top = 20
Random_Number = Application.WorksheetFunction.RandBetween(Bottom, Top)

End Sub

VBA Code to Generate Random Number in a Range in Excel

⧭ Output:

Run the code after inserting an extra line MsgBox Random_Number.

It’ll display a random number between 11 and 20.

Output to Generate a Random Number in a Range with Excel VBA

Read More: Excel Formula to Generate Random Number (5 examples)


Similar Readings


2. Generate Random Number in a Range with VBA Rnd Function

Now, we’ll generate random numbers within a range using the VBA Rnd function.

The syntax of the Rnd function is:

=Rnd ()

It generates a random number between 0 and 1.

To generate a random number between 1 and 100, the VBA code will be:

⧭ VBA Code:

Sub Random_Numbers_with_Rnd()

Bottom = 11
Top = 20
Random_Number = Bottom + Int(Rnd() * (Top - Bottom + 1))

End Sub

VBA Code to Generate a Random Number in a Range with Excel VBA

⧭ Output:

Again run the code after inserting an extra line MsgBox Random_Number.

It’ll display a random number between 11 and 20.

Read More: How to Generate Random Number with Excel VBA (4 Examples)


Generating Random Numbers in a Range with Repetition

Here we’ve got a data set with the names of 10 students in a school.

Data Set to Generate a Random Number in a Range with Excel VBA

There are 10 teams in the school consisting of numbers between 1 to 10. We need to assign each student to any of the 10 teams available randomly.

Therefore, we need to generate a series of random numbers between 1 to 10 in the range C4:C13 of the worksheet.

There may be more than one student in one group. So there may be repetitions.

We can accomplish this using both the RandBetween function and the Rnd function. But we’ll use the RandBetween function here.

If you wish, you can try the Rnd function on your own.

The VBA code with the RandBetween function will be:

⧭ VBA Code:

Sub Random_Numbers_with_Repetition()

Set Rng = Range("C4:C13")

Bottom = 1
Top = 10

For i = 1 To Rng.Rows.Count
    For j = 1 To Rng.Columns.Count
        Rng.Cells(i, j) = Application.WorksheetFunction.RandBetween(Bottom, Top)
    Next j
Next i

End Sub

⧭ Output:

Run this code. It’ll create a series of random numbers from 1 to 10 in the range C4:C13 of the worksheet with repetition.

Read More: How to Generate Random Numbers Without Duplicates in Excel (7 Ways)


Generating Random Numbers in a Range without Repetition

Now, we’ll assign each student a unique team. That means, we’ll generate a series of random numbers between 1 to 10 in the range C4:C13, this time without repetition.

We’ll use the Rnd function of VBA here.

⧭ VBA Code:

Sub Random_Numbers_without_Repetition()

Set Rng = Range("C4:C13")

Bottom = 1
Top = 10

Dim Numebrs() As Variant
ReDim Numbers(Top - Bottom)

For i = LBound(Numbers) To UBound(Numbers)
    Numbers(i) = Bottom + i
Next i

For i = 1 To Rng.Rows.Count
    For j = 1 To Rng.Columns.Count
        Index = LBound(Numbers) + Int(Rnd() * (UBound(Numbers) - LBound(Numbers) + 1))
        Rng.Cells(i, j) = Numbers(Index)
        For k = Index To UBound(Numbers) - 1
            Numbers(k) = Numbers(k + 1)
        Next k
        If UBound(Numbers) <> 0 Then
            ReDim Preserve Numbers(UBound(Numbers) - 1)
        End If
    Next j
Next i

End Sub

VBA Code to Generate a Random Number in a Range with Excel VBA

⧭ Output:

Run this code. It’ll create a series of random numbers from 1 to 10 in the range C4:C13 of the worksheet without repetition.

Read More: Random Number Generator in Excel with No Repeats (9 Methods)


Things to Remember

The Rnd function is a function of VBA. That’s why we used it directly in our codes. On the other hand, the RandBetween function is not a VBA function, it’s actually an Excel function. That’s why we had to use it along with the Application.WorksheetFunction property.


Conclusion

So, these are the ways to generate random numbers in a range using VBA in Excel. Do you have any questions? Feel free to ask us. And don’t forget to visit our site ExcelDemy for more posts and updates.


Related Articles

Rifat Hassan

Rifat Hassan

Hello! Welcome to my profile. Here I will be posting articles related to Microsoft Excel. I am a passionate Electrical Engineer holding a Bachelor’s degree in Electrical and Electronic Engineering from the Bangladesh University of Engineering and Technology. Besides academic studies, I always love to keep pace with the revolution in technology that the world is rushing towards day by day. I am diligent, career-oriented, and ready to cherish knowledge throughout my life.

We will be happy to hear your thoughts

Leave a reply

ExcelDemy
Logo