A method of predicting a capacity change of a battery includes calculating damage to cathode particles of a secondary battery during each charging/discharging cycle if the charging/discharging cycle is repeatedly performed in the secondary battery, calculating accumulated damage by accumulating the damage, calculating a minimum radius of the cathode particles in which a fatigue fracture occurs due to the accumulated damage, calculating, based on a distribution of radii of the cathode particles and the minimum radius, a reduction amount in a volume of a cathode active particle due to the fatigue fracture during each charging/discharging cycle, and calculating a relative capacity loss at a cathode based on the reduction amount in the volume of the cathode active particle during each charging/discharging cycle.