A method of calculating total power usage of a field programmable gate array (FPGA) without external components generates at least one coefficient based on a power equation and a given FPGA logic design, wherein the power equation calculates FPGA power as a function of temperature and voltage. The at least one coefficient is applied to the power equation along with internally generated temperature and voltage measurement values. The temperature measurement and the voltage measurement values are applied to the power equation with the at least one coefficient applied to calculate a power measurement based on the temperature measurement value and the voltage measurement value. The at least one coefficient is generated by taking an FPGA design and iteratively simulating the design in a power estimation tool over a range of temperature and input voltage values. A characterization data set is generated and curve fitted to the power equation to produce the at least one coefficient.