The runaway tokamak equilibrium is analysed numerically. The runaway electrons with distributed energy are modelled by multi-energy electron beams. The model equations include a self-consistent orbit analysis of the beams. This aspect improves the accuracy of the theory compared with the usual calculations of beam-plasma equilibrium which model the beam effect by an enhanced pressure parallel to the magnetic field. Deformations of a tokamak equilibrium due to the beam inertial effect are studied. The beam component achieves a betatron equilibrium in a total poloidal magnetic field due to the plasma current and the external equilibrium coils.