  The recent astronomical observations indicate that the expanding universe is
homogeneous, isotropic and asymptotically flat. The Euclidean geometry of the
universe enables to determine the total gravitational and kinetic energy of the
universe by Newtonian gravity in a flat space. By dimensional analysis, we have
found the mass of the universe close to the Hoyle-Carvalho formula M ~
c^3/(GH). This value is independent from the cosmological model and infers a
size (radius) of the universe close to Hubble distance. It has been shown that
almost the entire kinetic energy of the universe ensues from the cosmological
expansion. Both, the total gravitational and kinetic energies of the universe
have been determined in relation to an observer at an arbitrary location. The
relativistic calculations for total kinetic energy have been made and the dark
energy has been excluded from calculations. The total mechanical energy of the
universe has been found close to zero, which is a remarkable result. This
result supports the conjecture that the gravitational energy of the universe is
approximately balanced with its kinetic energy of the expansion.
