Abstract: A new type of bioclock calculating device for the human body comprising a ring, a set of discs and some accessories. They are marked with data graduation, age graduation and curves showing the cycles of physical, emotional and intellectual (PEI) rhythms. When superimposed eccentrically set into planetary revolutions, the discs will provide instant information about an individual's PEI rhythms on any day in any year and show the continual distribution of the curves over many years. It may also be used for a comparative study of PEI rhythms between two persons.