A respiration rate determining apparatus includes: an obtaining unit which obtains accelerations in directions that are mutually different, the accelerations being obtained by an acceleration sensor measuring a body movement by respiration of a user； a transform unit which transforms the accelerations in the directions obtained by the obtaining unit, into spectrum information items in a frequency domain； a phase removing unit which transforms the spectrum information items into amplitude spectra by removing phase information from the spectrum information items； a peak detector which adds up the amplitude spectra and detects a peak frequency based on an amplitude spectrum resulting from the adding up, the peak frequency indicating a respiratory component； and a respiration rate calculator which calculates a respiration rate using the peak frequency.
