F♯4 / G♭4
Reviewed for accuracy · Maintained by Justin Evans
F♯4 highlighted — use the view toggle to see all 88 keys.
Piano key
46 of 88
Octave
4
Frequency
369.99 Hz
MIDI number
66
Key color
Black key
Pitch class
F# · Gb · E##
What is F♯4?
F♯4 is the F♯ in octave 4 — the 46th key of the 88 on a full-size piano, counted from the bottom. In standard tuning it sounds at 369.99 Hz. It sits 6 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) within the same octave to reach octave 4, then step to F♯.
Every octave doubles the frequency: the F♯ one octave up sounds at 739.98 Hz and the one below at 185 Hz. The same piano key can be written as F#, Gb, E## depending on the musical context — same sound, different spelling.
Nearby notes
Every F♯ on the keyboard: