A♯5 / B♭5
Reviewed for accuracy · Maintained by Justin Evans
A♯5 highlighted — use the view toggle to see all 88 keys.
Piano key
62 of 88
Octave
5
Frequency
932.33 Hz
MIDI number
82
Key color
Black key
Pitch class
A# · Bb · Cbb
What is A♯5?
A♯5 is the A♯ in octave 5 — the 62nd key of the 88 on a full-size piano, counted from the bottom. In standard tuning it sounds at 932.33 Hz. It sits 22 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 A♯.
Every octave doubles the frequency: the A♯ one octave up sounds at 1864.66 Hz and the one below at 466.17 Hz. The same piano key can be written as A#, Bb, Cbb depending on the musical context — same sound, different spelling.
Nearby notes
Every A♯ on the keyboard: