Understanding the processes of variation of the population contingent of a given region is important and essential for related studies, mainly environmental planning issues. In this way, this article proposes to measure the population variation of a municipality, comparing two methods of population estimation, arithmetic and geometric, in order to choose the one that best quantified and represented the population changes of a region over the years. For this, census data from the years 1991, 2000 and 2010 were used, which were also used to create a growth forecast for the year 2020, through the application of statistical estimation methods. In order to carry out the estimation, the numerical database of demographic censuses was used, thus adapting the results to the statistical functions. In this way, the study resulted in the identification of the method provided a better result in the implementation of the calculations. Thus, between the two methods used the geometric method, presented a better response, regarding the behavior and expression of the data for the case study analyzed.