CHANGE FONT SIZES

 

1. Open the PowerPoint.
2. Go to Tools → Macro → Visual Basic Editor.
   If you have the Developer tab, you can also use Developer → Visual Basic.
3. Choose Insert → Module.
4. Paste this:

Sub IncreaseAllFontSizes()

    Dim sld As Slide
    Dim shp As Shape
    Dim IncreaseBy As Single

    IncreaseBy = 4   'Change this to 5, 6, etc. if you want

    For Each sld In ActivePresentation.Slides
        For Each shp In sld.Shapes
            IncreaseFontInShape shp, IncreaseBy
        Next shp
    Next sld

    MsgBox "All font sizes increased by " & IncreaseBy & " points!"

End Sub


Sub IncreaseFontInShape(shp As Shape, IncreaseBy As Single)

    Dim i As Long
    Dim r As Long
    Dim c As Long

    'Regular text boxes and placeholders
    If shp.HasTextFrame Then
        If shp.TextFrame.HasText Then
            shp.TextFrame.TextRange.Font.Size = _
                shp.TextFrame.TextRange.Font.Size + IncreaseBy
        End If
    End If

    'Tables
    If shp.HasTable Then
        For r = 1 To shp.Table.Rows.Count
            For c = 1 To shp.Table.Columns.Count
                If shp.Table.Cell(r, c).Shape.TextFrame.HasText Then
                    With shp.Table.Cell(r, c).Shape.TextFrame.TextRange.Font
                        .Size = .Size + IncreaseBy
                    End With
                End If
            Next c
        Next r
    End If

    'Grouped objects
    If shp.Type = msoGroup Then
        For i = 1 To shp.GroupItems.Count
            IncreaseFontInShape shp.GroupItems(i), IncreaseBy
        Next i
    End If

End Sub

Then close the Visual Basic window and go to Tools → Macro → Macros, select IncreaseAllFontSizes, and click Run.