Abstract: The invention is related to a series gear pump for differing output volumes with at least two gear pumps, each gear pump comprises at least two intermeshing displacing elements, a first displacing element and a second displacing element in the form of gears. The individual gear pumps of the series comprise a substantially identical dimensions for the axial interval between the theoretical axes and between the theoretical axes of rotation of the two displacing elements, and a substantially identical gearing width in the form of a substantially identical axial extension of the gearing elements. The individual gear pumps differ from each other at least as regards the size of the tip circle diameter of at least one of the two displacing elements.