Sub test()
Call AutoFitMergedCells(Range("A1:A3"))
End Sub
Public Sub AutoFitMergedCells(oRange As Range)
Dim tHeight As Integer
Dim iPtr As Integer
Dim oldWidth As Single
Dim oldZZWidth As Single
Dim newWidth As Single
Dim newHeight As Single
With Sheets("Sheet1")
oldWidth = 0
For iPtr = 1 To oRange.Columns.Count
oldWidth = oldWidth + .Cells(1, oRange.Column + iPtr - 1).ColumnWidth
Next iPtr
oldWidth = .Cells(1, oRange.Column).ColumnWidth + .Cells(1, oRange.Column + 1).ColumnWidth
oRange.MergeCells = False
newWidth = Len(.Cells(oRange.Row, oRange.Column).Value)
oldZZWidth = .Range("ZZ1").ColumnWidth
.Range("ZZ1") = Left(.Cells(oRange.Row, oRange.Column).Value, newWidth)
.Range("ZZ1").WrapText = True
.Columns("ZZ").ColumnWidth = oldWidth
.Rows("1").EntireRow.AutoFit
newHeight = .Rows("1").RowHeight / oRange.Rows.Count
.Rows(CStr(oRange.Row) & ":" & CStr(oRange.Row + oRange.Rows.Count - 1)).RowHeight = newHeight
oRange.MergeCells = True
oRange.WrapText = True
.Range("ZZ1").ClearContents
.Range("ZZ1").ColumnWidth = oldZZWidth
End With
End Sub