An apparatus for calibration of a bio-information estimation model includes a sensor configured to obtain a bio-signal from an object in a reference interval; a feature extractor, implemented by at least one processor, configure to extract a reference feature value from the bio-signal; and a calibrator, implemented by the at least one processor, configured to determine whether a condition is satisfied based on at least one of the reference feature value and an offset value, and based on determining that the condition is satisfied, configured to calibrate the bio-information estimation model based on the reference feature value and the offset value.