We have performed (i) measurements at T = 4 K and (ii) numerical simulations of the resistivity at T = 0 K for the itinerant amorphous magnetic alloys Fe1-xZrx over a large concentration region. The resistivities are measured with sputtered thin films and calculated numerically by direct evaluation of the Kubo formula for small, but realistic computer models, using a self-consistent semi-empirical approach for the description of the itinerant magnetism of the system. The numerical results for the total resistivity rho agree with the experiments, showing values around 170 muOMEGA cm, except for concentrations below x almost-equal-to 0.15, where resistivities around almost-equal-to 120 muOMEGA cm are found. Outside this region, in the magnetic state the contribution of carriers with minority spin polarization to the conductivity is significantly larger than that of electrons with majority spin, according to the calculations. Finally, the calculations suggest that this difference would also appear in the region of the small x-values for hydrogenated samples, e.g. for Fe0.93Zr0.07H0.14.