Adding numbers in a column - excel

Question

I have written this code to add numbers in a column. It is not adding the last cell.
For example if there are three numbers 1, 2 and 3 it will sum up 1 and 2 and ignore value in third cell. When there is a fourth number 1, 2, 3 and 4 it adds 1, 2 and 3.
Sub add()
Dim Rng As Range, a As Integer
Set Rng = Range("b2", Range("b2").End(xlDown))
Counter = Rng.Count
a = 0
For i = 2 To Counter
a = a + Cells(i, "B").Value
Next i
ActiveCell.Value = a
End Sub

Answer 1

Let's say the Counter = Rng.Count gives 4, and you start your i = 2 (possibly to keep title of your column). Your code will not print 4 digits, because you start loop from 2.
The counter should look like this:
Counter = Rng.Count + 1
and it will work

Answer 2

It is because .End(xlDown) - it works like CTRL + downarrow, and ends on the last not empty, or first not empty cell in the column. That's why when you delete value in specific row it will "break" the range. If you want to scan all rows, no matter if it's empty or not use the loop from the first row, and you will get the sum of the whole column range (starting from row 2 of course):
Sub SumWholeColumn()
'give the sum of all numbers in column B, starting from B2
Dim i, a As Long
Dim column, addr As String
a = 0
column = "b"
For i = 2 To Rows.Count
addr = column & i
a = a + Cells(i, "B").Value
Next i
ActiveCell.Value = a
End Sub
If your range is fixed, you can speed up the calculation process by setting the range manually. Otherwise it will scan ALL rows. For example if you know, that your random numbers will not exceed row 1000, then you can use something like this:
Sub SumWholeColumn()
'give the sum of all numbers in column B, starting from B2
Dim i, a As Long
Dim maxRows As Integer
Dim column, addr As String
a = 0
column = "b"
maxRows = 1000
For i = 2 To maxRows
addr = column & i
a = a + Cells(i, "B").Value
Next i
ActiveCell.Value = a
End Sub

Answer 3

Well I think that at the first time I did not understood your point then, I thought you would like to paste numbers in column B from 0 to the last row, starting from the B2 address. If so - this will work:
Sub add()
Dim i, a As Long
Dim column As String
Dim addr As String
a = 0
column = "b"
For i = 2 To Rows.Count
addr = column & i
ActiveSheet.Range(addr).Value = a
a = a + 1
Next i
End Sub
but today I realised that your title "Adding numbers in a column via Excel VBA
" is wrong and probably you are trying to achieve something else (because you are trying to give some value in ActiveCell?) and if so, please correct me:
you have actually some numbers in column B, and you would like to give in the ActiveCell the sum of all those numbers? The answer for this will be:
Sub SumAll()
'give the sum of all numbers in column B, starting from B2
Dim Rng As Range
Dim a, i As Long
Set Rng = Range("b2", Range("b2").End(xlDown))
Counter = Rng.Count + 1
a = 0
For i = 2 To Counter
a = a + Cells(i, "B").Value
Next i
ActiveCell.Value = a
End Sub
You need to use "a" as Long, because Integer is up to 2147483647 and if you fill all rows in the column, starting from 0 and iterate the number by 1 to the last row, and sum the values it will give you 2147319811 - out of the Integer scope.
i value can be Integer (not Long as in my example), because "i" max value will not exceed the scope (Workbook rows are limited to 1048576). You can safely change i to Integer and save some KB's of memory :)