VBA SUM function for multiple values in nth rows - vba

Question

I would like to ask how to SUM the values quickly, when they are separated 30 rows from each other?
I would like to sum 9 values and input the result in different column as per the code below:
Sub sum()
Range("EG12").Formula = "=Sum(C12,C282, C552, C822,C1092,C1362,C1632,C1902,C2172,C2442)"
Range("EG42").Formula = "=Sum(C42,C312,C582, C852,C1122,C1392,C1662,C1932,C2202,C2472)"
Range("EG72").Formula = "=Sum(C72,C342,C612, C882,C1152,C1422,C1692,C1962,C2232,C2502)"
Range("EG102").Formula = "=Sum(C102,C372,C642,C912,C1182,C1452,C1722,C1992,C2262,C2532)"
End Sub
Where as you may have notice every destination cell is located exactly 30 rows between each other (inner rows are empty or contains different values) likewise copied cells, that are located exactly 270 rows between each other (see the image attached).
I was trying to do formula like this:
Sub sum2()
Dim lastrow As Long, i As Integer, total As Double, finalsum As Double
lastrow = Range("C2442").End(xlUp).Row
For i = 30 To lastrow
total = total + WorksheetFunction.sum(Range("C12" & i & "EG12" & i))
Next
finalsum = total
End Sub
...but I've got "Method 2Range of object2_Global failed.
Does somebody have some idea about this?
Thanks & regards,

Answer 1

I didn t make it that pretty with the 170 sum but you should understand the point like this:
Sub test2()
Dim lastrow As Long, i As Long, finalsum As Long
lastrow = Range("C2442").End(xlUp).Row
finalsum = 0
For i = 12 To lastrow Step 30
Range("E" & i).Value = WorksheetFunction.Sum(Cells(i, 3).Value, Cells(i + 170, 3).Value, Cells(i + 2 * 170, 3).Value, Cells(i + 3 * 170, 3).Value, Cells(i + 4 * 170, 3).Value, Cells(i + 5 * 170, 3).Value, Cells(i + 6 * 170, 3).Value, Cells(i + 7 * 170, 3).Value, Cells(i + 8 * 170, 3).Value, Cells(i + 9 * 170, 3).Value)
finalsum = finalsum + Range("E" & i).Value
Next i
End Sub

Answer 2

Try it with loops and unions.
Option Explicit
Sub sum30by270()
Dim i As Long, j As Long, lr as long
Dim r1 As Range, r2 As Range
With Worksheets("sheet2")
lr = .cells(.rows.count, "C").end(xlup).row
Set r1 = .Cells(12, "C")
For i = 282 To lr Step 270
Set r1 = Union(r1, .Cells(i, "C"))
Next i
'Debug.Print r1.Address(0, 0)
Set r2 = .Cells(12, "EG")
For j = 42 To 102 Step 30
Set r2 = Union(r2, .Cells(j, "EG"))
Next j
'Debug.Print r2.Address(0, 0)
r2.Formula = "=sum(" & r1.Address(0, 0) & ")"
End With
End Sub

Answer 3

Few remarks:
lastrow = Range("C2442").End(xlUp).Row
is not the right usage, you might want to change it to:
'going from specified cell down until empty cell is met
lastrow = Range("C2442").End(xlDown).Row
or
'going from last cell in C column up, until first non-empty cell is met
lastrow = Range(Rows.Count, 3).End(xlUp).Row
Second issue, if you want to loop every 30 rows, you should do it like this (also remember about proper indentation of your code!):
For i = 12 To lastrow Step 30
total = total + WorksheetFunction.Sum(Range(Cells(i, 1), Cells(i, 5)))
Next
finalsum = total
"C12" & i & "EG12" & i - & operator is a string concatenation, not addition, this is why you might get unexpected result.

Answer 4

Well, thank you all guys for our contribution. I would like to add final working formula for this issue:
Sub sum_1to10()
Dim i As Long, j As Long, lr As Long
Dim r1 As Range, r2 As Range
With Worksheets("13")
lr = .Cells(.rows.Count, "C").End(xlUp).Row
Set r1 = .Cells(12, "C") 'First cell with data in my worksheet - [![enter image description here][1]][1] C12
For i = 12 To 2442 Step 270 ' From 1st cell with data to 10th cell in this order C2442
'When put "lr" instead 2442 the values will be calculated as per all worksheet data included (in my case it was down to 8377
Set r1 = Union(r1, .Cells(i, "C"))
Next i
Set r2 = .Cells(12, "Eh")
For j = 12 To 1086 Step 30 'First subsequent cell with data with 30 rows step e.g C42, C72, etc
' Value 1086 correspond to the last row in label with sum
Set r2 = Union(r2, .Cells(j, "EG"))
Next j
r2.Formula = "=sum(" & r1.Address(0, 0) & ")"
End With
End Sub
Hopefully I have understood it well.
I decided to modify this formula in order to divide my calculation on 3 separate parts. I am making these bulk calculation for every month, and I have divided it for 3 decades.