Interval Calculator — Musical Intervals

A musical interval is the distance between two pitches, measured in semitones or by interval name (e.g., major third, perfect fifth). In equal temperament, each semitone equals 100 cents, and an octave is 12 semitones (1200 cents).

Just intonation ratios represent the simple frequency ratios that produce the purest-sounding intervals. A perfect fifth is 3:2 (the second note vibrates 1.5 times as fast), while a major third is 5:4. Equal temperament slightly adjusts these ratios so all keys sound equally in tune.

This calculator shows ascending intervals (from the first note up to the second). A descending interval would be the complement: e.g., a descending perfect fifth from C is F, which is the same as an ascending perfect fourth.