The A 440 [Hz] Pitch Standard

In 1939, an International Conference met in London and unanimously adopted 440 Hz as the standard frequency for the pitch A4. That is the almost universal standard at present. In 1975, It was reaffirmed by the International Organization for Standardization. The National Institute of Standards and Technology (NIST) broadcasts a precise reference tone at frequency of 440 Hz on its short wave radio station WWV. Rossing reports Handel's tuning fork frequency to be at 422.5 Hz for that A, and Hayden, Mozart, Bach and Beethoven had pitch standards around that frequency.

The A4 440Hz is the internationally recognized pitch standard. However, there are some orchestra groups that specialize in the music of a given historical period and they use different standards, for example, for the baroque period music the standard was at 415Hz, the "Chorton pitch" standard was at 466Hz and "classical pitch" standard was at 430Hz.


Based upon the A 440 Hz frequency standard the frequencies of the notes, including the offset frequencies of the chromatic notes (sharps and flats) of the eight octaves on the piano are:

----- Octave 1 -----
C0 = 16.352 Hz
C# = 17.324 Hz
D0 = 18.354 Hz
D# = 19.445 Hz
E0 = 20.602 Hz
F0 = 21.827 Hz
F# = 23.125 Hz
G0 = 24.500 Hz
G# = 25.957 Hz
A0 = 27.500 Hz (lowest piano note)
A# = 29.135 Hz
B0 = 30.868 Hz
----- Octave 2 -----
C1 = 32.703 Hz
C# = 34.648 Hz
D1 = 36.708 Hz
D# = 38.891 Hz
E1 = 41.203 Hz
F1 = 43.564 Hz
F# = 46.249 Hz
G1 = 48.999 Hz
G# = 51.913 Hz
A1 = 55.000 Hz
A# = 58.270 Hz
B1 = 61.735 Hz
----- Octave 3 -----
C2 = 65.406 Hz
C# = 69.296 Hz
D2 = 73.416 Hz
D# = 77.782 Hz
E2 = 82.407 Hz
F2 = 87.307 Hz
F# = 92.499 Hz
G2 = 97.999 Hz
G# = 103.83 Hz
A2 = 110.00 Hz
A# = 116.54 Hz
B2 = 123.47 Hz
----- Octave 4 -----
C3 = 130.81 Hz
C# = 138.59 Hz
D3 = 146.83 Hz
D# = 155.56 Hz
E3 = 164.81 Hz
F3 = 174.61 Hz
F# = 185.00 Hz
G3 = 196.00 Hz
G# = 207.65 Hz
A3 = 220.00 Hz
A# = 233.08 Hz
B3 = 246.94 Hz
----- Octave 5 -----
C4 = 261.63 Hz (middle C)
C# = 277.18 Hz
D4 = 293.66 Hz
D# = 311.13 Hz
E4 = 329.63 Hz
F4 = 349.23 Hz
F# = 369.99 Hz
G4 = 392.00 Hz
G# = 415.30 Hz
A4 = 440.00 Hz
A# = 466.16 Hz
B4 = 493.88 Hz
----- Octave 6 -----
C5 = 523.25 Hz
C# = 554.37 Hz
D5 = 587.33 Hz
D# = 622.25 Hz
E5 = 659.26 Hz
F5 = 698.46 Hz
F# = 739.99 Hz
G5 = 783.99 Hz
G# = 830.61 Hz
A5 = 880.00 Hz
A# = 923.33 Hz
B5 = 987.77 Hz
----- Octave 7 -----
C6 = 1046.5 Hz
C# = 1108.7 Hz
D6 = 1174.7 Hz
D# = 1244.5 Hz
E6 = 1318.5 Hz
F6 = 1396.9 Hz
F# = 1480.0 Hz
G6 = 1568.0 Hz
G# = 1661.2 Hz
A6 = 1760.0 Hz
A# = 1864.7 Hz
B6 = 1975.5 Hz
----- Octave 8 -----
C7 = 2093.0 Hz
C# = 2217.5 Hz
D7 = 2349.3 Hz
D# = 2489.0 Hz
E7 = 2637.0 Hz
F7 = 2793.8 Hz
F# = 2960.0 Hz
G7 = 3136.0 Hz
G# = 3322.4 Hz
A7 = 3520.0 Hz
A# = 3729.3 Hz
B7 = 3951.1 Hz

C8 = 4186.0 Hz (top note on piano)