[en] Extrapolated ranges of electrons R_ex,t and R_ex,p have been determined from transmission and projected-range straggling curves, respectively. Data on the two kinds of curve have been obtained by Monte Carlo calculations for 0.1-50 MeV electrons incident on elemental absorbers of atomic numbers between 4 and 92. The two sets of extrapolated ranges, as well as another set, R_ex,q, determined from charge-deposition curves (Nucl. Instrum. Methods B 119 (4) (1996) 463), have been found practically the same. Appreciable differences of R_ex,t from R_ex,p and R_ex,q have been observed only for electrons of energies below 2 MeV incident on absorbers of the highest atomic numbers. The cause of these differences has been traced to the backscattering of electrons from the incident surface, phenomenon affecting only R_ex,t among the extrapolated ranges determined by the three methods. The fact that the extrapolated range is in most cases independent of the method of determination establishes the usefulness of this quantity. An analytic expression fitted to the Monte Carlo results of R_ex,t is given