Expressions for the diagonal components of the polarizability tensor, absorption cross sections, and dimensional dependences of the surface plasmon resonance frequencies of metal nanodisks are obtained in the work in the classical approximation. Calculations of the frequency and size dependences of these characteristics for disks of different metals and with different aspect ratios are presented. The influence of the aspect ratio on the evolution of the frequency dependences of the components of the polarizability tensor and absorption cross sections is analyzed. The most significant factors influencing the splitting of the surface plasmon resonance in metal nanodisks with a small asect ratio have been determined.