Abstract: An electronic calculator is disclosed for calculating important obstetrical dates based on the entry of certain variables or information. The electronic calculator is structured to accept input relating to the last menstrual period, conception date, estimated date of confinement and estimated gestational age. The entry of any one of these variables of information, along with the entry of a reference date, allows the calculator to calculate the other, remaining variables. The electronic calculator provides information similar to that conventionally obtained from an obstetric wheel or birth wheel, but additionally provides for the capability of recalculating and updating the obstetric dates based on new or additional information input into the calculator. The dates calculated using the invention are, therefore, more accurate and can be stored in memory for recall at each subsequent obstetrical visit.