A tool includes one or more machine readable storage mediums encoded with data. The data include a list of standard cells included in an integrated circuit (IC) design The data include a nominal leakage value approximating a respective median leakage value for each of the plurality of standard cells at a predetermined temperature and voltage. The data include at least one table including adjustment factors for calculating leakage based on voltage, temperature and process variations. The table includes a respective statistical scaling factor, for computing a mean leakage corresponding to a given median leakage. A processor is programmed to calculate and output a total IC leakage for the IC design at an input voltage and input temperature, based on the list, the nominal leakage values, the input voltage, the input temperature and at least one of the adjustment factors.