Despite the importance of the new science in the colonisation of Stuart Ireland, and the many Irish links to major figures in the Scientific Revolution, these connections remain relatively little studied outside of major episodes such as the Down Survey. This article examines a much smaller project, the ‘Computatio Universalis’ (1684) of Church of Ireland clergyman (later bishop of Down and Connor) Samuel Foley (1655–1695). Submitted to the Dublin Philosophical Society in 1684 as an attempt to ‘to demonstrate a universal standard’ of value, Foley’s project was in fact a guide to the achievement of ‘happiness’ through the careful stewardship of time and wealth. Foley’s project recalls earlier Christian humanist and Protestant concern with stewardship, however, and also reflects seventeenth-century economic writers’ and moral reformers’ concern with avoiding idleness. In the context of Restoration Ireland, however, it can also be seen more specifically as a project harnessing new methods of quantification for the cultural maintenance of a ruling Protestant elite historically threatened by degeneration in a colonial setting, as well as a reflection of Protestant anxieties about the Catholic church’s control over time.