C6
C6 highlighted — use the view toggle to see all 88 keys.
Piano key
64 of 88
Octave
6
Frequency
1046.5 Hz
MIDI number
84
Key color
White key
Pitch class
C, B#, Dbb
What is C6?
C6 is the C in octave 6 — the 64th key of the 88 on a full-size piano, counted from the bottom. In standard tuning it sounds at 1046.5 Hz. It sits 24 half-steps above middle C (C4).
To find it, locate any group of two black keys: the white key just to their left is a C. Count up from middle C (C4) 2 octaves to reach octave 6, then step to C.
Every octave doubles the frequency: the C one octave up sounds at 2093 Hz and the one below at 523.25 Hz. The same piano key can be written as C, B#, Dbb depending on the musical context — same sound, different spelling.
Nearby notes
Every C on the keyboard: