Note Frequency Reference — A4=440Hz Equal Temperament
This complete note frequency chart covers the entire MIDI range from C0 (MIDI 0, 16.35 Hz) to B8 (MIDI 107, 7902.13 Hz), based on the international standard of A4 = 440 Hz using equal temperament tuning. The table is useful for audio engineers setting up synthesizer oscillators, musicians understanding pitch relationships, and anyone working with digital audio.
A4 (440 Hz) is highlighted in blue. Each octave doubles the frequency: A3 = 220 Hz, A4 = 440 Hz, A5 = 880 Hz. This logarithmic relationship means our ears perceive consistent pitch intervals across all octaves.