A fuselage segment for an aircraft fuselage includes a wall with a closed cross section, a first cabin floor, a second cabin floor, and a cargo hold floor. The first cabin floor, the second cabin floor, and the cargo hold floor are vertically spaced apart from each other and connected to the wall. A first passenger region is arranged above the first cabin floor, a second passenger region is arranged above the second cabin floor, and a cargo region is arranged above the cargo hold floor. The cargo region is dimensioned in such a manner that for at least four passenger seats a maximum of 1 m3 of cargo hold volume is provided. In this manner an existing aircraft fuselage can be designed in a demand-oriented manner so that it can accommodate two or more passenger regions.