The electric meters used to measure the amount of electricity consumption measure both active and reactive power consumption in the distribution line with current transformers. As in every analog measurement process, in every analog measurement, existing of undesired components such as noises, interferences and harmonics are caused mistakes. In order to remove this undesirable information included in the measurement from the measurement results, digital filters are used in applications because of their performance and their easily replaceable features. In this study, we aimed to remove unwanted components such as noise and interference from the measurement signal. The subject of a commercial project is to design a digital filter in MATLAB® environment, which allows filtering the measurements of reactive power consumption in power distribution lines with less than 1% error. To ensure whether designed filter satisfies for mentioned criteria or not, we used the Gaussian model as a noise model because Gauss noise is spreaded whole frequency spectrum. While the power signal modeled in the design is a sine wave of Ipp = 2 A 50 Hz, Gaussian noise with different variances and mean values is used in modeling the unwanted components.