A rotor of an exhaust-gas turbocharger includes a rotor hub and rotor blades disposed on the rotor hub. The rotor blades have a blade thickness distribution selected in such a way that the rotor blades have along their extent from a fluid inlet or leading edge to a fluid outlet or trailing edge at least one transition between a stiffness or rigidity-oriented blade thickness distribution and an inertia and stress-oriented blade thickness distribution over the height of the blade.