Two design models illustrate the methodology used to obtain the acceptable ranges for a set of design parameters for a lithium-cooled tokamak blanket. The methodology can also be used to identify the limiting constraints for a particular design. For typical tokamaks, header diameter is ∼12 cm; coolant inlet velocity is found to be <0.1 m/s to maintain a reasonable hoop stress in the header. For the constant ’ model, where tubes are distributed to match the volumetric heat generation, the limiting constraints are found to be the total number of tubes and the maximum size of the headers that can fit radially in the blanket. The maximum first wall neutron loading is 7 MW/m2. For the constant Tmax model, where cooling channels are placed so that the peak temperatures between the channels are equal, the limiting constraint is found to be the thermal stress in the channel wall. The first wall neutron loading is found to be 2.1 MW/m2.