An electrosurgical system is disclosed. The system includes an electrosurgical forceps including first and second jaw members pivotally attached in opposing relation relative to one another, the jaw members relatively movable from a first, open position wherein the jaw members are disposed in spaced relation relative to one another to a second, clamping position wherein the jaw members cooperate to grasp tissue therebetween with a predetermined clamping force, each of the jaw members including an electrically conductive sealing surface. The system also includes an electrosurgical generator configured to operatively couple to the electrosurgical forceps and to supply electrosurgical energy to the electrically conductive sealing surfaces. The electrosurgical generator includes at least one input control configured to record a user-defined setting associated with the electrosurgical energy at least one sensor configured to measure at least one tissue parameter or at least one electrosurgical energy parameter and a controller configured to predict a tissue mass of the tissue grasped by the jaw members based on the at least one tissue parameter or at least one electrosurgical energy parameter and to adjust the user-defined setting as a function of the predicted tissue mass.