We show in this paper that the analytical erbium-doped fiber amplifier (EDFA) model presented by Jopson and Saleh in 1991 can be extended to the self-saturation regime, making it capable of simulating all practical EDFAs. We show that an Intel Pentium 66 based computer can calculate gain and noise figure for a counterdirectionally pumped self-saturated amplifier in <0.5 a when using the extended model as an effective noise bandwidth model. We compare the extended model with, the effective noise bandwidth model presented by Giles and Desurvire in 1991 and show identical results. Finally we demonstrate very good agreement between measurements and simulations based on measured fiber data for both high-gain EDFAs (small-signal gain of 35 dB) and isolator EDFAs (small-signal gain of 43 dB) with deviations <1 dB on the gain and <0.7 dB on the noise figure. (C) 1997 Academic Press.