The paper is devoted to the presentation of the applied calculation methods of one of the basic concepts of higher algebra, the rank of a matrix, as well as the description of the calculation of the rank of a matrix using the MAPLE computer package. In the present paper first the concept of matrix rank is introduced and then applied methods for calculating it by applying elementary transformations to the rows of the matrix and by determining a minor of the highest order other than 0 are presented. Specific examples of calculating the rank of a matrix are considered. In addition to practical methods for calculating the rank of a matrix, also the description of the implementation of calculating the rank of a matrix using the MAPLE computer package is introduced in the paper. The calculation of all matrix ranks, considered in the paper, is also carried out in the MAPLE environment, based on detailed guidelines, as a result of which it will be possible to instantly calculate the matrix rank.