A method for calculating a systolic blood pressure includes receiving data regarding pulse transit time (PTT) and a systolic blood pressure (SBP) of a patient group, extracting a correlation between parameters (a, y0) by analyzing results obtained by applying the data regarding the pulse transit time (PTT) and the systolic blood pressure (SBP) of the patient group to a PTT-SBP (Pulse Transit Time-Systolic Blood Pressure) relationship (SBP=a*PTT−1+y0), receiving data regarding a first pulse transit time (PTT) and a systolic blood pressure (SBP) of a measurement subject, and acquiring unique parameter values (a, y0) of the measurement subject by applying the correlation between the parameters (a, y0) and the data regarding the first pulse transit time (PTT) and the systolic blood pressure (SBP) of the measurement subject to the PTT-SBP relationship.
