A method of adjusting the closing force of a door coupled to a door closer assembly having a bias element. The method includes determining the kinetic energy of the door without using the weight or other dimensions of the door. The determined kinetic energy is used to adjust the closing force of an electro-mechanical door closer that includes a spring and a motor. The door includes the use of one, some of, or all of an accelerometer, an angular position sensor, a time to close, a breaking torque, and a controller to identify values a acceleration, velocity, and/or position of the door. The identified values are provided to the controller, which is configured to calculate the kinetic energy of the door. The calculated kinetic energy is used to determine the closing velocity of the door closure to ensure proper operation of the door at the point of installation.