property CalendarCombo.AutoSize as AutoSizeEnum
Retrieves or sets a value that indicates whether the control automatically resizes the cell based on the size of the font.

TypeDescription
AutoSizeEnum An AutoSizeEnum expression that indicates whether the control automatically resizes the cell based on the size of the font.

By default, the AutoSize property is exFontSize. The Font property specifies the control's font. The MaxMonthX property specifies the number of months that can displayed on the horizontal axis. The MaxMonthY property specifies the number of months that can displayed on the vertical axis. Use the AutoSize, FixedCellHeight and FixedCellWidth properties to defines the size of the control's cell. A cell displays a date. The FixedCellHeight and FixedCellWidth properties has effect only if the AutoSize is False.  

The following sample fixes the cell's size to (18,32): 

Private Sub Form_Load()
    With CalendarCombo1
        .AutoSize = exFixedSize
        .FixedCellHeight = 18
        .FixedCellWidth = 32
    End With
End Sub