A method for determining a predicted lesion size formed in a tissue by receiving or calculating a measure of contact force between the electrode and the tissue, determining a tissue characterization, and calculating the predicted lesion size using both the measure of contact force and the tissue characterization. A system comprising an electronic control unit configured to receive or determine a measure of contact force between the electrode and the tissue, characterize the tissue based on both the measure of impedance and the measure of contact force, and cause the tissue characterization to be either (a) presented to a user, or (b) applied to calculate a metric and cause the metric to be presented to the user.