How to find the true Last Cell in any Worksheet

Question

This question is now answered elegantly, thanks to Chris Neilsen, see the answer below. It is the one I will use from now on. The solution reliably finds the last cell in

Answer 1

Based on @Gary's method, but optimised to work fast when the UsedRange is Large but not reflective of the True Last Cell (as can happen when a cell on the extreames of a worksheet is inadvertently formatted)

It works by, starting with the UsedRange, counting cells in half the range and halving the referenced test range above or below the split point depending on the count result, and repeating until it reaches < 5 rows/columns, then uses a linear search from there.

Function TrueLastCell( _
  ws As Excel.Worksheet, _
  Optional lRealLastRow As Long, _
  Optional lRealLastColumn As Long _
  ) As Range
    Dim lrTo As Long, lcTo As Long, i As Long
    Dim lrFrom As Long, lcFrom As Long
    Dim wf As WorksheetFunction
    Set wf = Application.WorksheetFunction

    With ws.UsedRange
        lrTo = .Rows.Count
        lcTo = .Columns.Count

        lrFrom = lrTo \ 2
        Do While (lrTo - lrFrom) > 2
            If wf.CountA(.Rows(lrFrom & ":" & lrTo)) = 0 Then
                lrTo = lrFrom - 1
                lrFrom = lrFrom \ 2
            Else
                lrFrom = (lrTo + lrFrom) \ 2
            End If
        Loop

        If wf.CountA(.Rows(lrFrom & ":" & lrTo)) = 0 Then
            lrTo = lrFrom - 1
        Else
            For i = lrTo To lrFrom Step -1
                If wf.CountA(.Rows(i)) <> 0 Then
                    Exit For
                End If
            Next i
            lrTo = i
        End If

        lcFrom = lcTo \ 2
        Do While (lcTo - lcFrom) > 2
            If wf.CountA(Range(.Columns(lcFrom), .Columns(lcTo))) = 0 Then
                lcTo = lcFrom - 1
                lcFrom = lcFrom \ 2
            Else
                lcFrom = (lcTo + lcFrom) \ 2
            End If
        Loop


        If wf.CountA(Range(.Columns(lcFrom), .Columns(lcTo))) = 0 Then
            lcTo = lcFrom - 1
        Else
            For i = lcTo To 1 Step -1
                If wf.CountA(.Columns(i)) <> 0 Then
                    Exit For
                End If
            Next i
            lcTo = i
        End If

        Set TrueLastCell = .Cells(lrTo, lcTo)
        lRealLastRow = lrTo + .Row - 1
        lRealLastColumn = lcTo + .Column - 1
    End With
End Function

On my hardware it runs in about 2ms on a sheet with UsedRange extending to the sheet limits and True Last Cell at F5, and 0.1ms when UsedRange reflects the True Last Cell at F5

Edit: slightly more optimised search