| Note | Octave | Frequency (Hz) | MIDI Number | |
|---|---|---|---|---|
| C0 | 0 | 16.35 | 12 | |
| C#/Db0 | 0 | 17.32 | 13 | |
| D0 | 0 | 18.35 | 14 | |
| D#/Eb0 | 0 | 19.45 | 15 | |
| E0 | 0 | 20.60 | 16 | |
| F0 | 0 | 21.83 | 17 | |
| F#/Gb0 | 0 | 23.12 | 18 | |
| G0 | 0 | 24.50 | 19 | |
| G#/Ab0 | 0 | 25.96 | 20 | |
| A0 | 0 | 27.50 | 21 | |
| A#/Bb0 | 0 | 29.14 | 22 | |
| B0 | 0 | 30.87 | 23 | |
| C1 | 1 | 32.70 | 24 | |
| C#/Db1 | 1 | 34.65 | 25 | |
| D1 | 1 | 36.71 | 26 | |
| D#/Eb1 | 1 | 38.89 | 27 | |
| E1 | 1 | 41.20 | 28 | |
| F1 | 1 | 43.65 | 29 | |
| F#/Gb1 | 1 | 46.25 | 30 | |
| G1 | 1 | 49.00 | 31 | |
| G#/Ab1 | 1 | 51.91 | 32 | |
| A1 | 1 | 55.00 | 33 | |
| A#/Bb1 | 1 | 58.27 | 34 | |
| B1 | 1 | 61.74 | 35 | |
| C2 | 2 | 65.41 | 36 | |
| C#/Db2 | 2 | 69.30 | 37 | |
| D2 | 2 | 73.42 | 38 | |
| D#/Eb2 | 2 | 77.78 | 39 | |
| E2 | 2 | 82.41 | 40 | |
| F2 | 2 | 87.31 | 41 | |
| F#/Gb2 | 2 | 92.50 | 42 | |
| G2 | 2 | 98.00 | 43 | |
| G#/Ab2 | 2 | 103.83 | 44 | |
| A2 | 2 | 110.00 | 45 | |
| A#/Bb2 | 2 | 116.54 | 46 | |
| B2 | 2 | 123.47 | 47 | |
| C3 | 3 | 130.81 | 48 | |
| C#/Db3 | 3 | 138.59 | 49 | |
| D3 | 3 | 146.83 | 50 | |
| D#/Eb3 | 3 | 155.56 | 51 | |
| E3 | 3 | 164.81 | 52 | |
| F3 | 3 | 174.61 | 53 | |
| F#/Gb3 | 3 | 185.00 | 54 | |
| G3 | 3 | 196.00 | 55 | |
| G#/Ab3 | 3 | 207.65 | 56 | |
| A3 | 3 | 220.00 | 57 | |
| A#/Bb3 | 3 | 233.08 | 58 | |
| B3 | 3 | 246.94 | 59 | |
| C4 | 4 | 261.63 | 60 | |
| C#/Db4 | 4 | 277.18 | 61 | |
| D4 | 4 | 293.66 | 62 | |
| D#/Eb4 | 4 | 311.13 | 63 | |
| E4 | 4 | 329.63 | 64 | |
| F4 | 4 | 349.23 | 65 | |
| F#/Gb4 | 4 | 369.99 | 66 | |
| G4 | 4 | 392.00 | 67 | |
| G#/Ab4 | 4 | 415.30 | 68 | |
| A4 | 4 | 440.00 | 69 | |
| A#/Bb4 | 4 | 466.16 | 70 | |
| B4 | 4 | 493.88 | 71 | |
| C5 | 5 | 523.25 | 72 | |
| C#/Db5 | 5 | 554.37 | 73 | |
| D5 | 5 | 587.33 | 74 | |
| D#/Eb5 | 5 | 622.25 | 75 | |
| E5 | 5 | 659.26 | 76 | |
| F5 | 5 | 698.46 | 77 | |
| F#/Gb5 | 5 | 739.99 | 78 | |
| G5 | 5 | 783.99 | 79 | |
| G#/Ab5 | 5 | 830.61 | 80 | |
| A5 | 5 | 880.00 | 81 | |
| A#/Bb5 | 5 | 932.33 | 82 | |
| B5 | 5 | 987.77 | 83 | |
| C6 | 6 | 1046.50 | 84 | |
| C#/Db6 | 6 | 1108.73 | 85 | |
| D6 | 6 | 1174.66 | 86 | |
| D#/Eb6 | 6 | 1244.51 | 87 | |
| E6 | 6 | 1318.51 | 88 | |
| F6 | 6 | 1396.91 | 89 | |
| F#/Gb6 | 6 | 1479.98 | 90 | |
| G6 | 6 | 1567.98 | 91 | |
| G#/Ab6 | 6 | 1661.22 | 92 | |
| A6 | 6 | 1760.00 | 93 | |
| A#/Bb6 | 6 | 1864.66 | 94 | |
| B6 | 6 | 1975.53 | 95 | |
| C7 | 7 | 2093.00 | 96 | |
| C#/Db7 | 7 | 2217.46 | 97 | |
| D7 | 7 | 2349.32 | 98 | |
| D#/Eb7 | 7 | 2489.02 | 99 | |
| E7 | 7 | 2637.02 | 100 | |
| F7 | 7 | 2793.83 | 101 | |
| F#/Gb7 | 7 | 2959.96 | 102 | |
| G7 | 7 | 3135.96 | 103 | |
| G#/Ab7 | 7 | 3322.44 | 104 | |
| A7 | 7 | 3520.00 | 105 | |
| A#/Bb7 | 7 | 3729.31 | 106 | |
| B7 | 7 | 3951.07 | 107 | |
| C8 | 8 | 4186.01 | 108 | |
| C#/Db8 | 8 | 4434.92 | 109 | |
| D8 | 8 | 4698.64 | 110 | |
| D#/Eb8 | 8 | 4978.03 | 111 | |
| E8 | 8 | 5274.04 | 112 | |
| F8 | 8 | 5587.65 | 113 | |
| F#/Gb8 | 8 | 5919.91 | 114 | |
| G8 | 8 | 6271.93 | 115 | |
| G#/Ab8 | 8 | 6644.88 | 116 | |
| A8 | 8 | 7040.00 | 117 | |
| A#/Bb8 | 8 | 7458.62 | 118 | |
| B8 | 8 | 7902.13 | 119 |
Adjust the reference frequency (A4) to recalculate all note frequencies. Use the octave filter to display specific octaves only, and click 'Play' to hear each note.
It is the international standard pitch where the A above middle C (A4) is tuned to 440 Hz. Most instruments and orchestras tune to this reference.
An alternative tuning where A4 is set to 432 Hz instead of 440 Hz. Some musicians prefer it for its warmer, more natural sound.
MIDI (Musical Instrument Digital Interface) numbers are standardized note identifiers. Middle C (C4) is 60, and A4 is 69. They are the standard in electronic music and computer-based instruments.
Sound is the vibration of air, and the speed of that vibration (frequency) determines pitch. The unit of frequency is Hertz (Hz), where 1 Hz means one vibration per second. The human hearing range is approximately 20 Hz to 20,000 Hz, and most notes used in music fall between 27 Hz (A0) and 4,186 Hz (C8). When frequency doubles, the pitch rises by exactly one octave. For example, A5 — one octave above A4 (440 Hz) — is 880 Hz.
Modern Western music is based on 12-tone Equal Temperament. It divides one octave evenly into 12 semitones, with a constant frequency ratio between each semitone of the 12th root of 2 (approximately 1.05946). Thanks to this system, the interval relationships remain identical in any key, allowing free transposition. Most modern instruments — piano, guitar, orchestra — are tuned to equal temperament. However, alternative tuning systems that follow the natural harmonic series, such as Just Intonation, also exist.
A4 = 440 Hz is the pitch standard adopted as the international norm in 1939. Before this standard, different countries and eras used different references — in the Baroque period, around A4 = 415 Hz was commonly used. Today, some orchestras tune to A4 = 442 Hz or 444 Hz for a brighter tone. Some guitarists and vocalists prefer A4 = 432 Hz. In this frequency calculator, changing the reference frequency recalculates all note frequencies to that standard.