MIDI · Hz · Scientific · Solfège · Helmholtz
Free Musical Notes Converter
Convert MIDI note numbers to frequencies (Hz) and note names instantly. Enter any MIDI number or frequency and get Scientific pitch, Solfège, Helmholtz, octave, and more. Free.
Why symmetrical conversion?
How This Converter Works
MIDI maps notes to integers 0–127. Frequencies double with each octave. Enter a MIDI number or Hz frequency and instantly see the note name in Scientific, Solfège (Do-Re-Mi), and Helmholtz notation, plus octave, pitch class, and wavelength.
Quick reference
Common Conversions
| MIDI | Note | Frequency (Hz) | Scientific Pitch |
|---|---|---|---|
| 57 | A3 | 220.00 Hz | A below middle C |
| 60 | Middle C | 261.63 Hz | C₄ — universally referenced |
| 69 | Concert A | 440.00 Hz | A₄ — international tuning standard |
| 72 | C5 | 523.25 Hz | One octave above middle C |
| 84 | C6 | 1046.50 Hz | Two octaves above middle C |
| 127 | G9 | 12,543.85 Hz | Highest MIDI note |
FAQ
Frequently Asked Questions
1What is MIDI?
MIDI (Musical Instrument Digital Interface) is a protocol that maps musical notes to integer values 0–127. It does not transmit audio — it transmits instructions telling instruments which note to play, how hard, and for how long.
2How is frequency related to MIDI notes?
Each MIDI number step is one semitone. Every 12 semitones (one octave) doubles the frequency. The formula is: f = 440 × 2^((MIDI−69)/12). Middle C (MIDI 60) = 261.63 Hz.
3What is Middle C in MIDI?
Middle C is MIDI note 60. Its frequency is 261.63 Hz. It is called C₄ in Scientific Pitch Notation, Do₄ in Solfège. Note: some DAWs display it as C3 or C5 depending on their octave numbering.
4What is Concert A (A440)?
Concert A is MIDI note 69, frequency 440 Hz. It is the international standard tuning reference (ISO 16). All instruments in an ensemble tune to this pitch. It is A₄ in Scientific notation.
Related converters