Based on the spectral observations of the LAMOST (DR2) survey, the radii, masses, and luminosities of 700480 stars were estimated. These stars belong to spectral types A, F, G, and K, and have metallicities between -0.845 and 0.0. To determine the properties of the stars, we used up-to-date modelsof the stellar interior structure, computed with account for the stellar evolution rate and the initial mass function. The use of evolutionary estimates for two types of stars - with and without rotation - allowed us to account for the uncertainty associated with the lack of data on the rotation velocity of the stars under consideration. The obtained stellar radii, together with the photometric estimates of interstellar extinction and angular diameters can be used to study the dependence of interstellar extinction on distance as well as to estimate the stellar distances.