Magnetic adhesion is widely used in wall climbing robots on ferromagnetic surfaces. The Ring and block Neodymium magnets provide the necessary adhesion in permanent magnet-based climbing robots. In this article, the effectiveness of ring and block magnets are analysed using FEMM. for various magnet configurations. The adhesion force generated by ring and block magnets of a similar volume is compared and analysed. The results showed that the adhesion of ring magnets increases with the thickness of magnets. The maximum adhesion achieved in various ring magnets was compared with the adhesion generated by the arrangement of block magnets for two standoff distances and it was found that the adhesion generated by the block magnets were better in both cases. The ring magnets have constant standoff distance as per the rubber coating used and this enables them to operate seamlessly on irregular surfaces while the block magnet configurations provide excellent payload capabilities. In summary, numerical simulation results provided an understanding of the areas where the ring magnets can be used and the areas where the block magnets serve the purpose better.