How the MIDI frequency calculator works
Convert MIDI note number to frequency (or the reverse) using equal temperament and a selectable A4 reference-standard for tuning instruments and synthesizers.
Key terms
- MIDI note 69 - A4 at 440 Hz by convention.
- Equal temperament - each semitone is a factor of 2^(1/12).
- Period - time of one cycle; inverse of frequency.
Frequently asked questions
- What MIDI note is A4? MIDI note 69, conventionally 440 Hz when A4 reference is 440 Hz.