A system for computing solar radiation seen by an individual (I), comprising: portable location means (2) for locating and tracking the position (P) of an individual (I) in the course of a day of direct or indirect exposure to the sun； data-collection means (1) containing satellite data (d2) regarding solar radiation in the traced position of the individual； computing means (3) operatively connected to said location means (2) and to said data-collection means (1) for receiving data (d1) regarding the position of the individual and data (d2) regarding solar radiation on the ground in the same position where the individual is in order to compute the dose (R1) of solar radiation seen by the individual and to compute a dose (R3) of solar radiation that is missing or is in excess with respect to an expected dose (R2) corresponding to a desired personal circadian rhythm of the individual (I).
