Two methods are described to obtain the value of the series resistance<tex>(R)</tex>of a Schottky diode from its forward I-V characteristic. The value of<tex>R</tex>is then used to plot the curve ln (<tex>I</tex>) versus<tex>V_{D} (= V - IR)</tex>which becomes a straight line even if ln<tex>(I)</tex>versus<tex>V</tex>does not. The ideality factor<tex>n</tex>and the Schottky-barrier height<tex>\Phi_{B0}</tex>of the diode then follow from the standard procedure. The main advantages of the methods are: 1) a linear regression can be used to calculate the value of<tex>R</tex>, 2) many data points are used over the whole data range which raises the accuracy of the results, and 3) the validity of constant<tex>R</tex>assumption can be checked by the linearity of the ln<tex>(I)</tex>versus V<inf>D</inf>curve. The methods are illustrated on the experimental data of a real diode.