C♯5 / D♭5
Reviewed for accuracy · Maintained by Justin Evans
C♯5 highlighted — use the view toggle to see all 88 keys.
Piano key
53 of 88
Octave
5
Frequency
554.37 Hz
MIDI number
73
Key color
Black key
Pitch class
C# · Db · B##
What is C♯5?
C♯5 is the C♯ in octave 5 — the 53rd key of the 88 on a full-size piano, counted from the bottom. In standard tuning it sounds at 554.37 Hz. It sits 13 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 1108.74 Hz and the one below at 277.19 Hz. The same piano key can be written as C#, Db, B## depending on the musical context — same sound, different spelling.
Nearby notes
Every C♯ on the keyboard: