An apparatus for estimating blood pressure is provided. The apparatus for estimating blood pressure may include: a bio-signal measurer configured to measure a bio-signal from a user; and a processor configured to extract one or more feature values from the bio-signal, to adjust a combination coefficient for combining the one or more feature values based on a reference value associated with vascular compliance, and to estimate blood pressure based on the adjusted combination coefficient, and the one or more feature values extracted from the bio-signal.