An apparatus for estimating bio-information, the apparatus comprising: a sensor (110, 620, 730) configured to obtain a bio-signal of a user; and a processor configured to: obtain a heart rate from the obtained bio-signal; detect a heart rate variation compared to a reference heart rate measured in a resting state of the user at a reference time; estimate a variation in a cardiac output, CO,-related feature based on the heart rate variation; obtain a progressive wave component, which is associated with a total peripheral resistance, TPR,-related feature, from different positions of the bio-signal according to whether the variation in the CO-related feature is large or small, wherein the variation in the CO-related feature is estimated to be large, if the heart rate variation exceeds a predetermined threshold value, and the variation in the CO-related feature is estimated to be small, if the heart rate variation is less than or equal to the predetermined threshold value, wherein the processor is further configured to: estimate the CO-related feature from the bio-signal, estimate the TPR-related feature based on the obtained progressive wave component, and estimate blood pressure by applying a predetermined blood pressure estimation model that defines a correlation between the CO-related feature, the TPR-related feature and blood pressure. a sensor (110, 620, 730) configured to obtain a bio-signal of a user; and a processor configured to: obtain a heart rate from the obtained bio-signal; detect a heart rate variation compared to a reference heart rate measured in a resting state of the user at a reference time; estimate a variation in a cardiac output, CO,-related feature based on the heart rate variation; obtain a progressive wave component, which is associated with a total peripheral resistance, TPR,-related feature, from different positions of the bio-signal according to whether the variation in the CO-related feature is large or small, wherein the variation in the CO-related feature is estimated to be large, if the heart rate variation exceeds a predetermined threshold value, and the variation in the CO-related feature is estimated to be small, if the heart rate variation is less than or equal to the predetermined threshold value, wherein the processor is further configured to: estimate the CO-related feature from the bio-signal, estimate the TPR-related feature based on the obtained progressive wave component, and estimate blood pressure by applying a predetermined blood pressure estimation model that defines a correlation between the CO-related feature, the TPR-related feature and blood pressure. obtain a heart rate from the obtained bio-signal; detect a heart rate variation compared to a reference heart rate measured in a resting state of the user at a reference time; estimate a variation in a cardiac output, CO,-related feature based on the heart rate variation; obtain a progressive wave component, which is associated with a total peripheral resistance, TPR,-related feature, from different positions of the bio-signal according to whether the variation in the CO-related feature is large or small, wherein the variation in the CO-related feature is estimated to be large, if the heart rate variation exceeds a predetermined threshold value, and the variation in the CO-related feature is estimated to be small, if the heart rate variation is less than or equal to the predetermined threshold value, wherein the processor is further configured to: estimate the CO-related feature from the bio-signal, estimate the TPR-related feature based on the obtained progressive wave component, and estimate blood pressure by applying a predetermined blood pressure estimation model that defines a correlation between the CO-related feature, the TPR-related feature and blood pressure. estimate the CO-related feature from the bio-signal, estimate the TPR-related feature based on the obtained progressive wave component, and estimate blood pressure by applying a predetermined blood pressure estimation model that defines a correlation between the CO-related feature, the TPR-related feature and blood pressure.