A turbine rotor for a gas turbine engine includes a disk rotationally disposed about a central axis. The disk includes a bore disposed about the central axis, a rim and a web disposed radially between the bore and the rim. The bore has a fore surface and an aft surface. The aft surface of the bore may include an aft web transition portion, an aft ramp portion radially inward of the aft web transition portion and an aft base transition portion radially inward of the aft ramp portion. The fore surface of the bore may include a fore web transition portion, a fore ramp portion radially inward of the fore web transition portion and a fore base transition portion radially inward of the fore ramp portion. The aft ramp portion includes a substantially linear portion and the fore ramp portion includes a substantially linear portion.