MinimumScaleIsAuto Property
True if Microsoft Excel calculates the minimum value for the axis. Read/write Boolean.
Remarks
Setting the MinimumScale property sets this property to False.
Example
This example automatically calculates the minimum scale and the maximum scale for the value axis in Chart1.
With Charts("Chart1").Axes(xlValue)
.MinimumScaleIsAuto = True
.MaximumScaleIsAuto = True
End With