A turbine blade is disclosed. The turbine blade may include a platform, an airfoil extending from one side of the platform, and a neck extending from another side of the platform, wherein the neck includes a forward buttress and an aft buttress. The turbine blade may further include a root extending from the neck, a pocket defined by a plurality of walls and located between the forward buttress and the aft buttress, and a variable radius fillet. The variable radius fillet may be disposed within the pocket and extend between the forward buttress and the aft buttress, wherein a radius of the variable radius fillet increases from the forward buttress to the aft buttress.