This paper presents the story of two calculating machines invented by Sir Samuel Morland (1625–95) in the 1660s. These instruments are the earliest known mechanical calculators made in England. Their designs are unusual and very much of their time. They appealed to some, especially at court, and were dismissed by others, such as Robert Hooke. The first part of the paper introduces Morland and the courtier–inventor's world, in which a reputation as a ‘machinist’ or an engineer could accompany high social status. It considers why a former diplomat and postal spy would turn to invention in general and to mechanical calculators in particular as a career move in the Restoration court. The second part addresses the instruments – attention to their design reveals Morland's inspiration. The paper concludes with an examination of the market for the calculators in London, Paris and Florence. While it is notable that the calculators circulated both in court and in the commercial sphere, even more interesting is the contrast between their receptions in these two spheres. The story of these machines and their maker helps flesh out the poorly understood world of the courtier–inventor in early modern England.