Convert a MIDI note number into its exact frequency in hertz.
MIDI note 69 is the tuning note A4, and each semitone up doubles the frequency after twelve steps. Synth patches, sample pitch and tuning software all rely on this equal-tempered relationship between note number and hertz.
MIDI Note to Frequency
Frequency = 440 x 2^((MIDI-69)/12)
Frequency = 440 x 2^((MIDI-69)/12) MIDI note 69 is the tuning note A4, and each semitone up doubles the frequency after twelve steps.
Synth patches, sample pitch and tuning software all rely on this equal-tempered relationship between note number and hertz.
This calculator takes 2 inputs: MIDI note number, A4 tuning. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.