Simulations of magnetization processes can be very useful tools for designing new magnetic materials. It is of great importance to include atomic properties in considerations for studying magnetization processes of dimensionally real systems, i.e., mesoscopic in size. The presented MC method, with a disorder-based cluster approach, is suitable for multimagnetic systems, but the system size (counted in nodes) is restricted to 105–106 nodes, which means that only nano-objects can be analyzed. In order to enlarge this size, we propose re-scaling of the system using a concentration of the volume nr × nr × nr (n is the scaling factor, r is inter-node distance) into one node. The new system contains the same number of nodes but all its linear dimensions are enlarged by the n factor. Simultaneously, it is necessary to recalculate the system parameters occurring in a Hamiltonian, which is used for energy change calculation. On the whole, we propose scaling rules, which save energetic equivalence between rotation of the re-scaled magnetic moment and a group of spins in the nr × nr × nr volume. Additionally, we have found that the MC iterations can be carried out under the thermodynamic balance determined for the “reduced” system, similar to the initial one but with an exchange integral parameter equal to Jij/n.