Excel VBA - Need to grab a variable size of rows - excel

Question

New to VBA - Recorded the macro below and every time I run it it always selects 309 rows. I am wanting the rows to be fluid (Example: Could be 400 rows, could be 10 depending on data.
Columns("H:H").Select
`Selection.Style = "Comma"
Range("I2").Select
Selection.EntireColumn.Insert
Range("H1").Select
Selection.Copy
Range("I1").Select
ActiveSheet.Paste
Range("I2").Select
Application.CutCopyMode = False
ActiveCell.FormulaR1C1 = "=IF(RC[-3]=""C"",RC[-1]*-1,RC[-1])"
Range("I2").Select
Selection.AutoFill Destination:=Range("I2:I309")
Range("I2:I309").Select
Columns("I:I").Select
Selection.Copy
Range("I1").Select
Selection.PasteSpecial Paste:=xlPasteValues, Operation:=xlNone, SkipBlanks _
:=False, Transpose:=False
Range("H4").Select
Application.CutCopyMode = False
Selection.EntireColumn.Delete
Range("L7").Select
Selection.EntireColumn.Insert
Range("K1").Select
Selection.Copy
Range("L1").Select
ActiveSheet.Paste
Range("L2").Select
Application.CutCopyMode = False
ActiveCell.FormulaR1C1 = "=RIGHT(RC[-1],4)"
Range("L3").Select
ActiveWindow.SmallScroll Down:=-12
Range("L2").Select
Selection.AutoFill Destination:=Range("L2:L309")
Range("L2:L309").Select
Columns("L:L").Select
Selection.Copy
Range("L1").Select
Selection.PasteSpecial Paste:=xlPasteValues, Operation:=xlNone, SkipBlanks _
:=False, Transpose:=False
Range("K2").Select
Application.CutCopyMode = False
Selection.EntireColumn.Delete
Range("M23").Select
Sheets.Add After:=ActiveSheet
Sheets("Sheet1").Select
Range("K2").Select
Range(Selection, Selection.End(xlDown)).Select
Selection.Copy
Sheets("Sheet2").Select
Range("C2").Select
Selection.PasteSpecial Paste:=xlPasteValues, Operation:=xlNone, SkipBlanks _
:=False, Transpose:=False
Sheets("Sheet1").Select
Range("C281").Select
Selection.End(xlUp).Select
Range("D2").Select
Range(Selection, Selection.End(xlDown)).Select
Application.CutCopyMode = False
Selection.Copy
Sheets("Sheet2").Select
Range("D2").Select
Selection.PasteSpecial Paste:=xlPasteValues, Operation:=xlNone, SkipBlanks _
:=False, Transpose:=False
Range("D2").Select
Range(Selection, Selection.End(xlDown)).Select
Application.CutCopyMode = False
Selection.NumberFormat = "m/d/yyyy"
Range("C2:D2").Select
Range(Selection, Selection.End(xlDown)).Select
ActiveSheet.Range("$C$2:$D$309").RemoveDuplicates Columns:=Array(1, 2), _

Answer 1

There's too much going on here for me to translate all of this code for you, but I believe the word you're looking for here is dynamic. In order to replace 309 with a dynamic last row number, you'll need to change:
Selection.AutoFill Destination:=Range("I2:I309")
to
Selection.AutoFill Destination:=Range("I2:I" & Cells(Rows.Count, "I").End(xlUp).Row)
and
Selection.AutoFill Destination:=Range("L2:L309")
to
Selection.AutoFill Destination:=Range("L2:L" & Cells(Rows.Count, "L").End(xlUp).Row)
etcetera, etcetera. Also like #cybernetic.nomad said, you should read that link he shared with you.