This article presents a study on the real radius of a hydrogen atom based on experimental data and modern theoretical models. According to the experimental results shown in Figure 4 (c), the radius of the hydrogen atom in the unexcited state is 1.0 mm, and in Figure 4 (b) in the excited state it is 1.4 mm [1]. These values ​​were reduced to real scales, which corresponds to radii of 1.0 Å and 1.4 Å for the unexcited and excited states, respectively. Three theoretical models were considered: the Bohr model, Schrödinger method within the framework of quantum mechanics, and Deterministic Theory of Atoms (DTA) developed by Bakhodir Tursunbayev. The results obtained demonstrate that DTA provides more accurate predictions of the radii of the hydrogen atom than the Bohr and Schrödinger models. This article also recommends promoting this new theory in the scientific community.