The value of the AutoScaleBaseSize property is used at form-display time to compute the scaling factor for the form. The autoscaling base size is used by the form as a baseline for comparison to the system's font size to determine how much to scale the form when autoscaling is used. If you want to determine the size a form will auto scale to based on a specific font, use the GetAutoScaleSize method.
Note The value of this property is used when the form is initially created. Once the property is set, it cannot be changed.