Abstract: A device having a keyboard and a display for determining and displaying information relating to the cost of telephone calls. The device contains information as to the identify of exchanges which may be called, as well as information as to the cost parameters of telephone calls placed from a predetermined exchange which is usually the exchange of the user's telephone. The device has an idle state in which a telephone number may be entered and an operating mode may be selected. The device has Timer, Verify and D.E.N. operating modes in each of which telephone cost information may be based on the rates of any of four long distance carriers. In all of these modes the device displays the exchange of the (local or non-local) telephone number entered and information as to one or more cost parameters associated with a call to the telephone number entered.