Note frequency chart: C2 to C6
The frequency of every note from C2 to C6 in equal temperament with A4 = 440 Hz, the tuning reference in ISO 16. Use it to check a tuner, set a reference tone, or see what your sung note means in hertz.
The formula
Each semitone multiplies the frequency by the twelfth root of 2 (about 1.0595). With the MIDI note number n (A4 = 69): f = 440 × 2(n − 69)/12 Hz. An octave up doubles the frequency: A3 = 220 Hz, A4 = 440 Hz, A5 = 880 Hz.
Chart
| Note | MIDI | Frequency | Period |
|---|---|---|---|
| C2 | 36 | 65.41 Hz | 15.29 ms |
| C#2 | 37 | 69.30 Hz | 14.43 ms |
| D2 | 38 | 73.42 Hz | 13.62 ms |
| D#2 | 39 | 77.78 Hz | 12.86 ms |
| E2 | 40 | 82.41 Hz | 12.13 ms |
| F2 | 41 | 87.31 Hz | 11.45 ms |
| F#2 | 42 | 92.50 Hz | 10.81 ms |
| G2 | 43 | 98.00 Hz | 10.20 ms |
| G#2 | 44 | 103.83 Hz | 9.63 ms |
| A2 | 45 | 110.00 Hz | 9.09 ms |
| A#2 | 46 | 116.54 Hz | 8.58 ms |
| B2 | 47 | 123.47 Hz | 8.10 ms |
| C3 | 48 | 130.81 Hz | 7.64 ms |
| C#3 | 49 | 138.59 Hz | 7.22 ms |
| D3 | 50 | 146.83 Hz | 6.81 ms |
| D#3 | 51 | 155.56 Hz | 6.43 ms |
| E3 | 52 | 164.81 Hz | 6.07 ms |
| F3 | 53 | 174.61 Hz | 5.73 ms |
| F#3 | 54 | 185.00 Hz | 5.41 ms |
| G3 | 55 | 196.00 Hz | 5.10 ms |
| G#3 | 56 | 207.65 Hz | 4.82 ms |
| A3 | 57 | 220.00 Hz | 4.55 ms |
| A#3 | 58 | 233.08 Hz | 4.29 ms |
| B3 | 59 | 246.94 Hz | 4.05 ms |
| C4 | 60 | 261.63 Hz | 3.82 ms |
| C#4 | 61 | 277.18 Hz | 3.61 ms |
| D4 | 62 | 293.66 Hz | 3.41 ms |
| D#4 | 63 | 311.13 Hz | 3.21 ms |
| E4 | 64 | 329.63 Hz | 3.03 ms |
| F4 | 65 | 349.23 Hz | 2.86 ms |
| F#4 | 66 | 369.99 Hz | 2.70 ms |
| G4 | 67 | 392.00 Hz | 2.55 ms |
| G#4 | 68 | 415.30 Hz | 2.41 ms |
| A4 | 69 | 440.00 Hz | 2.27 ms |
| A#4 | 70 | 466.16 Hz | 2.15 ms |
| B4 | 71 | 493.88 Hz | 2.02 ms |
| C5 | 72 | 523.25 Hz | 1.91 ms |
| C#5 | 73 | 554.37 Hz | 1.80 ms |
| D5 | 74 | 587.33 Hz | 1.70 ms |
| D#5 | 75 | 622.25 Hz | 1.61 ms |
| E5 | 76 | 659.26 Hz | 1.52 ms |
| F5 | 77 | 698.46 Hz | 1.43 ms |
| F#5 | 78 | 739.99 Hz | 1.35 ms |
| G5 | 79 | 783.99 Hz | 1.28 ms |
| G#5 | 80 | 830.61 Hz | 1.20 ms |
| A5 | 81 | 880.00 Hz | 1.14 ms |
| A#5 | 82 | 932.33 Hz | 1.07 ms |
| B5 | 83 | 987.77 Hz | 1.01 ms |
| C6 | 84 | 1046.50 Hz | 0.96 ms |
Values are rounded to two decimals. Sharps are written with #; the same key has a flat name too (C# = D♭). Middle C is C4 = 261.63 Hz.
Why your tuner may differ slightly
Some orchestras and recordings tune A4 a little higher or lower than 440 Hz, and older recordings can run fast or slow. A difference of a few hertz near A4 is only a handful of cents — see what cents mean.