We have investigated the performance of a method called the Reference Step Method at low voltage levels. The method has been evaluated earlier at voltage levels from 0.1 V to 1 kV with excellent results. The advantages of this method are that it uses commonly available equipment and can be fully automated. We have made comparisons with three other lowvoltage methods and the differences show that the uncertainties can be less than 30 μV/V at 1 mV and 3 μV/V at 10 mV, making it possible to use this method to perform automated calibration of calibrators with sufficient accuracy for calibration of high-end instruments.Index Terms -DC voltage ratio, dc range calibrators, dc voltage scale, dc voltage build-up, low voltage measurements.