I will show the calculation of the probability distribution of the volume of the Universe after inflation. Through a method that can be applied both to normal slow-roll and to eternal inflation, I will show in detail what happens to the probability distribution during the phase transition to eternal inflation confirming and extending previous results. The calculation also allows us to confirm and sharpen a recent bound on the number of e-foldings, enforcing at the quantitative level the analogy between the breaking of the effective theory at the end of black-hole evaporation and in the transition to eternal inflation.