C♯7 / D♭7
Reviewed for accuracy · Maintained by Justin Evans
C♯7 highlighted — use the view toggle to see all 88 keys.
Piano key
77 of 88
Octave
7
Frequency
2217.46 Hz
MIDI number
97
Key color
Black key
Pitch class
C# · Db · B##
What is C♯7?
C♯7 is the C♯ in octave 7 — the 77th key of the 88 on a full-size piano, counted from the bottom. In standard tuning it sounds at 2217.46 Hz. It sits 37 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) 3 octaves to reach octave 7, then step to C♯.
Every octave doubles the frequency: the C♯ one octave up sounds at 4434.92 Hz and the one below at 1108.73 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: