Virial masses within some radius in a galaxy system tend to undervalue the true total
mass. Here, we quantify this effect for the standard mass M(r 200 ) up to the radius
within which the mean density is 200ρ crit . We derive the masses up to the zero-gravity
radius r max , for a few common density profile laws: the isothermal, the Hernquist, and
the Navarro–Frenk–White profiles, relative to the mass M(r 200 ). Graphs show how
much mass could be missed at different radii, which can be a few M(r 200 ) up to the
zero-gravity radius r max . One result is that less-concentrated halos can be larger and
more massive up to r max , relative to M(r 200 ). These data are useful for applications
involving masses of galaxy systems and haloes.