A fan rotor includes a rotor body that has plurality of fan blades for rotation about a central axis. An annular wall extends radially inward from the rotor body. A hub body extends axially from the annular wall and defines a central hub bore with a hub bore diameter Db. The hub body further defines a first cylindrical hub portion on one axial side of the annular wall and a second cylindrical hub portion on an opposite side of the annular wall. A ratio of the outer diameter of the first cylindrical hub portion to a diameter of the central hub bore is 1.996-2.007, and a ratio of the second cylindrical hub portion outer diameter to the hub bore diameter is 2.051-2.063.