Browser-local music theory tool
Music Interval Calculator
Choose two note spellings and a direction. See their sounding semitone distance plus a simple interval name where the spelling supports it.
Choose two notes
How it works
The sounding distance is the difference between pitch classes modulo 12 in the chosen direction. The note letters determine the diatonic interval number; comparison with its major/perfect baseline determines the quality when unambiguous. For example C→D♯ and C→E♭ both sound three semitones apart, but spell as Augmented Second and Minor Third respectively.
Example and limits
C→D is two semitones, Major Second. C→F♯ is six semitones, Augmented Fourth. C→G♭ is six semitones, Diminished Fifth.
Only pitch classes are entered. The calculator cannot know register or whether two equal pitch classes are unison versus octave. Some unusual enharmonic spellings need explicit octave context and are reported as such.
Privacy
Inputs and generated results stay in this browser tab. This tool does not submit content, place inputs in the URL, or save them in browser storage. Audio tools use local Web Audio only and request no microphone access.