Within the framework of the classical one-dimensional theory of detonation based on conservation laws, the lower branch of the adiabat of energy release of the combustible mixture as a geometric place of the points of the final state of the system admits a solution for combustion waves whose propagation velocity Dfl ranges from zero to the deflagration velocity: 0 ⩽ Dfl ⩽ Ddef. The normal burning wave propagation velocity Su is located in this interval (0 ⩽ Su ⩽ Ddef), but it is traditionally calculated with the use of the thermal theory of combustion rather than detonation theory. Various approaches to choosing the final state point on the lower branch of the energy release adiabat for normal burning are analyzed in the present paper. Estimates are provided both for the degree of correspondence of the predicted and experimental velocities of flame propagation and for the degree of correspondence of the qualitative behavior of these dependences on the basis parameters of the mixture. For most hydrocarbon fuels considered in the study, the best agreement with the experimental data on Su is provided by the formula defining the flame velocity Dfl as the mean geometric value between the diffusion velocity Sdiff and deflagration velocity Ddef.