Question

I have a couple of colleagues looking at some bad code in Excel VBA, wondering is there a limit to the number of levels in a call stack

Answer 1

Unless the function is tail-recursive and VBA can handle that (which it can’t), you’ll run into a stack overflow.

As a simple test I hacked together the following snippet:

Dim count As Integer

Sub Rec()
    count = count + 1
    Cells(1, 1) = count
    Call Rec
End Sub

which tells us that the limit for this is 4007 iterations, at least in my version of Excel 2007 here.