Inflatable structures, composed of very thin membranes, have the unique capability to form intricate shapes once deployed. Their lightweight nature and low mass make them a preferred alternative to traditional solid structures, especially in the aerospace industry. This preference is due to their benefits, such as compact storage, ease of deployment, and cost-effectiveness, for specific aerospace missions. In this work, analytical formula has been derived for the deformation of an inflatable beam using mechanics-based approach. The validation of results is carried out by comparing analytical formulation with the deformation equations obtained from energy-based methods. Dynamic study is also carried out to find the natural frequencies of the structure. The mechanical characterization thus obtained offers a broad range of design possibilities by exploring different design parameters and providing active control strategies. This expanded design space enables the development of more efficient, adaptable, and advanced structures that can better meet the specific needs of various applications.