A method of correcting an error in a measured blood pressure includes measuring a blood pressure at a first site of a first body, calculating, using a processor, the error in the blood pressure measured at the first site of the first body based on a correlation between a shape of a sphygmogram measured at a first body part and a difference between a blood pressure measured at the first body part and a blood pressure measured at a second body part, where the correlation is predetermined using a statistical method based on a plurality of data from the blood pressure measured at the first body part and the blood pressure measured at the second body part, and correcting, using the processor, the blood pressure measured at the first site of the first body using the error calculated based on the correlation.
