  A review of measurements of the total cross section in ppbar collisions at
the TEVATRON and an outlook on the expected performance for similar
determinations at the LHC is given. The experimental method is based on the
optical theorem to determine the total cross section independent of the machine
luminosity. It consists of the extrapolation of the t-spectrum for elastic
scattering to t-->0 with a simultaneous measurement of the total inelastic
rate.
