Setting up loop in Excel VBA to repeatedly sum up specific range

Question

I have a spreadsheet where I'm trying to repeatedly populate column K with specific data from various but similar points (80 cells down for each iteration) in column E.

So K2 should for example display the total of E25 + E35 + E42 + E56 + E63.

Then K3 should display the total of E105 + E185 + E122 + E136 + E143.

I have written a macro which does the first step (and works), which is as follows:

Sub disctoptest()

Dim source As Range
Dim destination As Range
Dim total As Long

Set destination = Range("K2")
Set source = Range("E25")

total = WorksheetFunction.Sum( _
source.Value + _
source.Offset(10, 0).Value + _
source.Offset(17, 0).Value + _
source.Offset(31, 0).Value + _
source.Offset(38, 0).Value)

destination.Select

destination.Value = total

Set source = Nothing
Set destination = Nothing

End Sub

Then I inserted a loop to repeat the operation for the entirety of the database, but whenever I run the added macro excel either freezes or simply refuses to work. This is the code I'm using to loop:

Sub disctop()

Dim source As Range
Dim destination As Range
Dim total As Long

Set destination = Range("K2")
Set source = Range("E25")

Do until destination.offset(0, -1) = ""

destination.Select

total = WorksheetFunction.Sum( _
source.Value + _
source.Offset(10, 0).Value + _
source.Offset(17, 0).Value + _
source.Offset(31, 0).Value + _
source.Offset(38, 0).Value)

destination.Value = total

source = source.Offset(80, 0)
destination = destination.Offset(1, 0)

Loop

Range("A1").Activate

Set source = Nothing
Set destination = Nothing

End Sub

In case it might be easier to use a different kind of loop, I need to repeat the operation precisely 680 times in column K.

Any tips and advice would be greatly appreciated!

Answer 1

You need to use SET on the range variables to make them change to which cell they reference:

Set source = source.Offset(80, 0)
Set destination = destination.Offset(1, 0)

Also

destination.offset(0, -1) = "" will never return true as the SUM function will return 0 even when all five references are empty.

So you will need to test something else like: Total = 0

---

Or you can do this with the following formula:

 =INDEX(E:E,25+((ROW(1:1)-1)*80)) +INDEX(E:E,35+((ROW(1:1)-1)*80)) +INDEX(E:E,42+((ROW(1:1)-1)*80)) + INDEX(E:E,56+((ROW(1:1)-1)*80)) +INDEX(E:E,63+((ROW(1:1)-1)*80))

Put in K2 and copy down.