For many applications, it is important to transfer a given amount of heat with minimum possible volume of heat exchanger for a given pressure loss and effectiveness. In this study, optimum design of crossflow staggered tube banks for prescribed pressure loss and effectiveness is carried out. For this purpose, the method of Gnielinski-Gaddis is used for the calculation of heat transfer coefficient and pressure loss in tube banks. By prescribing the tube diameter, heat exchanger effectiveness, and pressure loss of the heat exchanger, the pitch length and tube number in the flow direction are determined for the condition of the maximum heat flow per heat exchanger volume. For a given value of total heat to be transferred, the length, height, and width of the heat exchanger can be determined by the equations that are derived using appropriate dimensionless numbers.