The staff to patient ratio in nursing refers to the number of patients assigned to a nurse during a specific shift. This ratio can vary widely depending on the type of healthcare facility, the unit within the facility, and the acuity level of the patients. For instance, in intensive care units (ICUs), the ratio might be 1:1 or 1:2, whereas in a general medical-surgical unit, it might be 1:4 or 1:5.