The following table summarizes the MIDI note numbers as defined in the MIDI standard and matched to the Middle C (note number 60) as C4.
## **What is the formula for note frequency?**
$Freq = note \times 2 N/12$
where N is the number of notes away from the start in connecting the MIDI note number and the base frequency – assuming equal tuning based on
$A4=a’=440 Hz$ – is:
$f = 440 \cdot 2^{\left(\right. n – 69 \left.\right) / 12}$
Formula Breakdown
– **`f`**: The frequency (in Hertz, Hz) of the note you want to find.
– **`f₀`**: The frequency of your known reference note (e.g., A4 = 440 Hz).
– **`n`**: The number of semitones (half steps) the target note is _above_ (positive) or _below_ (negative) the reference note.
– **`2^(n/12)`**: This part calculates the ratio. Going up 12 semitones (an octave) gives you `2^(12/12) = 2`, doubling the frequency.
Example: Finding the frequency of A#4 (A sharp in the 4th octave)
1. **Reference**: A4 = 440 Hz (`f₀`).
2. **Distance**: A#4 is 1 semitone above A4, so `n = 1`.
3. **Calculation**: `f = 440 Hz * (2^(1/12))` ≈ 466.16 Hz.
Example: Finding the frequency of C5 (Middle C an octave up)
1. **Reference**: A4 = 440 Hz (`f₀`).
2. **Distance**: C5 is 3 semitones above A4 (A4 -> A#4 -> B4 -> C5), so `n = 3`.
3. **Calculation**: `f = 440 Hz * (2^(3/12))` ≈ 523.25 Hz.
| **MIDI note number** | **Key number (Organ)** | **Key number (Piano)** | **Note names (English)** | | **Frequency (Equal tuning at 440 Hz)** |
| ————————– | ———————- | ———————- | ———————— | — | ————————————– |
| *top of MIDI tuning range* | | | G#9/Ab9 | | 13289.75 |
| 127 | | | G9 | | 12543.85 |
| 126 | | | F#9/Gb9 | | 11839.82 |
| 125 | | | F9 | | 11175.30 |
| 124 | | | E9 | | 10548.08 |
| 123 | | | D#9/Eb9 | | 9956.06 |
| 122 | | | D9 | | 9397.27 |
| 121 | | | C#9/Db9 | | 8869.84 |
| 120 | | | C9 | | 8372.02 |
| 119 | | | B8 | | 7902.13 |
| 118 | | | A#8/Bb8 | | 7458.62 |
| 117 | | | A8 | | 7040.00 |
| 116 | | | G#8/Ab8 | | 6644.88 |
| 115 | | | G8 | | 6271.93 |
| 114 | | | F#8/Gb8 | | 5919.91 |
| 113 | | | F8 | | 5587.65 |
| 112 | | | E8 | | 5274.04 |
| 111 | | | D#8/Eb8 | | 4978.03 |
| 110 | | | D8 | | 4698.64 |
| 109 | | | C#8/Db8 | | 4434.92 |
| 108 | | 88 | C8 | | 4186.01 |
| 107 | | 87 | B7 | | 3951.07 |
| 106 | | 86 | A#7/Bb7 | | 3729.31 |
| 105 | | 85 | A7 | | 3520.00 |
| 104 | | 84 | G#7/Ab7 | | 3322.44 |
| 103 | | 83 | G7 | | 3135.96 |
| 102 | | 82 | F#7/Gb7 | | 2959.96 |
| 101 | | 81 | F7 | | 2793.83 |
| 100 | | 80 | E7 | | 2637.02 |
| 99 | | 79 | D#7/Eb7 | | 2489.02 |
| 98 | | 78 | D7 | | 2349.32 |
| 97 | | 77 | C#7/Db7 | | 2217.46 |
| 96 | 61 | 76 | C7 | | 2093.00 |
| 95 | 60 | 75 | B6 | | 1975.53 |
| 94 | 59 | 74 | A#6/Bb6 | | 1864.66 |
| 93 | 58 | 73 | A6 | | 1760.00 |
| 92 | 57 | 72 | G#6/Ab6 | | 1661.22 |
| 91 | 56 | 71 | G6 | | 1567.98 |
| 90 | 55 | 70 | F#6/Gb6 | | 1479.98 |
| 89 | 54 | 69 | F6 | | 1396.91 |
| 88 | 53 | 68 | E6 | | 1318.51 |
| 87 | 52 | 67 | D#6/Eb6 | | 1244.51 |
| 86 | 51 | 66 | D6 | | 1174.66 |
| 85 | 50 | 65 | C#6/Db6 | | 1108.73 |
| 84 | 49 | 64 | C6 | | 1046.50 |
| 83 | 48 | 63 | B5 | | 987.77 |
| 82 | 47 | 62 | A#5/Bb5 | | 932.33 |
| 81 | 46 | 61 | A5 | | 880.00 |
| 80 | 45 | 60 | G#5/Ab5 | | 830.61 |
| 79 | 44 | 59 | G5 | | 783.99 |
| 78 | 43 | 58 | F#5/Gb5 | | 739.99 |
| 77 | 42 | 57 | F5 | | 698.46 |
| 76 | 41 | 56 | E5 | | 659.26 |
| 75 | 40 | 55 | D#5/Eb5 | | 622.25 |
| 74 | 39 | 54 | D5 | | 587.33 |
| 73 | 38 | 53 | C#5/Db5 | | 554.37 |
| 72 | 37 | 52 | C5 | | 523.25 |
| 71 | 36 | 51 | B4 | | 493.88 |
| 70 | 35 | 50 | A#4/Bb4 | | 466.16 |
| 69 | 34 | 49 | A4 concert pitch | | 440.00 |
| 68 | 33 | 48 | G#4/Ab4 | | 415.30 |
| 67 | 32 | 47 | G4 | | 392.00 |
| 66 | 31 | 46 | F#4/Gb4 | | 369.99 |
| 65 | 30 | 45 | F4 | | 349.23 |
| 64 | 29 | 44 | E4 | | 329.63 |
| 63 | 28 | 43 | D#4/Eb4 | | 311.13 |
| 62 | 27 | 42 | D4 | | 293.66 |
| 61 | 26 | 41 | C#4/Db4 | | 277.18 |
| 60 | 25 | 40 | C4 (middle C) | | 261.63 |
| 59 | 24 | 39 | B3 | | 246.94 |
| 58 | 23 | 38 | A#3/Bb3 | | 233.08 |
| 57 | 22 | 37 | A3 | | 220.00 |
| 56 | 21 | 36 | G#3/Ab3 | | 207.65 |
| 55 | 20 | 35 | G3 | | 196.00 |
| 54 | 19 | 34 | F#3/Gb3 | | 185.00 |
| 53 | 18 | 33 | F3 | | 174.61 |
| 52 | 17 | 32 | E3 | | 164.81 |
| 51 | 16 | 31 | D#3/Eb3 | | 155.56 |
| 50 | 15 | 30 | D3 | | 146.83 |
| 49 | 14 | 29 | C#3/Db3 | | 138.59 |
| 48 | 13 | 28 | C3 | | 130.81 |
| 47 | 12 | 27 | B2 | | 123.47 |
| 46 | 11 | 26 | A#2/Bb2 | | 116.54 |
| 45 | 10 | 25 | A2 | | 110.00 |
| 44 | 9 | 24 | G#2/Ab2 | | 103.83 |
| 43 | 8 | 23 | G2 | | 98.00 |
| 42 | 7 | 22 | F#2/Gb2 | | 92.50 |
| 41 | 6 | 21 | F2 | | 87.31 |
| 40 | 5 | 20 | E2 | | 82.41 |
| 39 | 4 | 19 | D#2/Eb2 | | 77.78 |
| 38 | 3 | 18 | D2 | | 73.42 |
| 37 | 2 | 17 | C#2/Db2 | | 69.30 |
| 36 | 1 | 16 | C2 | | 65.41 |
| 35 | | 15 | B1 | | 61.74 |
| 34 | | 14 | A#1/Bb1 | | 58.27 |
| 33 | | 13 | A1 | | 55.00 |
| 32 | | 12 | G#1/Ab1 | | 51.91 |
| 31 | | 11 | G1 | | 49.00 |
| 30 | | 10 | F#1/Gb1 | | 46.25 |
| 29 | | 9 | F1 | | 43.65 |
| 28 | | 8 | E1 | | 41.20 |
| 27 | | 7 | D#1/Eb1 | | 38.89 |
| 26 | | 6 | D1 | | 36.71 |
| 25 | | 5 | C#1/Db1 | | 34.65 |
| 24 | | 4 | C1 | | 32.70 |
| 23 | | 3 | B0 | | 30.87 |
| 22 | | 2 | A#0/Bb0 | | 29.14 |
| 21 | | 1 | A0 | | 27.50 |
| 20 | | | | | 25.96 |
| 19 | | | | | 24.50 |
| 18 | | | | | 23.12 |
| 17 | | | | | 21.83 |
| 16 | | | | | 20.60 |
| 15 | | | | | 19.45 |
| 14 | | | | | 18.35 |
| 13 | | | | | 17.32 |
| 12 | | | | | 16.35 |
| 11 | | | | | 15.43 |
| 10 | | | | | 14.57 |
| 9 | | | | | 13.75 |
| 8 | | | | | 12.98 |
| 7 | | | | | 12.25 |
| 6 | | | | | 11.56 |
| 5 | | | | | 10.91 |
| 4 | | | | | 10.30 |
| 3 | | | | | 9.72 |
| 2 | | | | | 9.18 |
| 1 | | | | | 8.66 |
| 0 | | | | | 8.18 |
Note that some manufacturers label middle C as C3.