The ActualSize property on a Field object indicates the actual length of a field's value. This property returns a returns a Long value.
size = field.ActualSize
The ActualSize property is used to return the actual length of a Field object's value. For all fields, the ActualSize property is read-only. If ADO cannot determine the length of the Field object's value, the ActualSize property returns adUnknown.
The ActualSize and DefinedSize properties on a Field object can be different. For example, a Field object with a declared type of adVarChar (variable character data type) and a maximum length of 50 characters returns a DefinedSize property value of 50, but the ActualSize property value it returns is the length of the data stored in the field for the current record.