C5
Reviewed for accuracy · Maintained by Justin Evans
C5 highlighted — use the view toggle to see all 88 keys.
Piano key
52 of 88
Octave
5
Frequency
523.25 Hz
MIDI number
72
Key color
White key
Pitch class
C · B# · Dbb
What is C5?
C5 is the C in octave 5 — the 52nd key of the 88 on a full-size piano, counted from the bottom. In standard tuning it sounds at 523.25 Hz. It sits 12 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) 1 octave to reach octave 5, then step to C.
Every octave doubles the frequency: the C one octave up sounds at 1046.5 Hz and the one below at 261.63 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: