A method for determining event based energy weights for digital power estimation includes obtaining a reference energy value corresponding to a power consumed by at least a portion of an integrated circuit (IC) device during operation. The method includes determining and selecting a subset of signals from a set of all signals within the IC that correlates to energy use within the IC. The method includes determining an activity factor of each signal in the subset by monitoring each signal while simulating execution of a particular set of instructions. The method includes determining a weight factor or at least an approximation of a weight factor for each signal in the subset by solving within a predetermined accuracy, a multivariable equation in which the reference energy value equals a weighted sum of the activity of the signals of the selected subset multiplied by their respective weight factors.