MIDI Note Number Calculator
The MIDI protocol identifies every pitch by an integer from 0 to 127. Understanding MIDI note numbers is essential for writing MIDI scripts, programming synthesizers, working with DAW automation, and debugging MIDI data. This calculator converts between note names (such as C4 or F#3) and their MIDI note numbers using the formula: MIDI = 12 * (octave + 1) + semitone. You can also enter a MIDI number to look up the corresponding note name. Middle C (C4) = 60, concert A (A4) = 69.
MIDI note number formula
MIDI = 12 * (octave + 1) + semitone
Semitone: C=0, C#=1, D=2, D#=3, E=4, F=5,
F#=6, G=7, G#=8, A=9, A#=10, B=11
Reverse: octave = floor(MIDI/12) - 1; semitone = MIDI mod 12
MIDI note numbers run from 0 (C-1) to 127 (G9). Middle C (C4) = 60. Concert A (A4) = 69. Piano range: MIDI 21 (A0) to 108 (C8).
Key MIDI note reference points
- MIDI 0: C-1 (below audible piano range)
- MIDI 21: A0 (lowest piano key)
- MIDI 60: C4 (middle C)
- MIDI 69: A4 (concert pitch, 440 Hz)
- MIDI 108: C8 (highest standard piano key)
- MIDI 127: G9 (highest MIDI note)
MIDI note numbers: frequently asked questions
What is a MIDI note number?
MIDI note numbers are integers from 0 to 127 used in the MIDI protocol to identify pitches. Note 0 is C-1 (the lowest representable pitch), note 60 is Middle C (C4), and note 127 is G9. The MIDI specification is defined by the MIDI Association.
What is the formula for MIDI note numbers?
MIDI note = 12 * (octave + 1) + semitone, where semitone: C=0, C#=1, D=2, D#=3, E=4, F=5, F#=6, G=7, G#=8, A=9, A#=10, B=11. So A4 = 12*(4+1)+9 = 69.
What is Middle C in MIDI?
Middle C is MIDI note 60. In standard MIDI convention, this is C4 (the C in octave 4). Some software labels it C3 or C5 depending on the octave numbering convention used.
What is the MIDI note range?
The MIDI standard defines 128 note numbers: 0 through 127. Note 0 is C-1 and note 127 is G9. A standard 88-key piano spans MIDI notes 21 (A0) through 108 (C8).
Why do some DAWs show different octave numbers?
The MIDI spec does not mandate a fixed octave numbering. Middle C (MIDI 60) is called C4 in Ableton, Logic, and GarageBand but C3 in some older Roland and Korg synthesizers. This calculator uses the C4 = MIDI 60 convention.
Official sources
- MIDI Association: MIDI 1.0 Detailed Specification - official MIDI note number standard.
- Audio Engineering Society (AES): aes.org - audio standards reference.
Reviewed by the CalculatorHub team, edited by James Graham, 15 June 2026. See our methodology.