F4
Reviewed for accuracy · Maintained by Justin Evans
F4 highlighted — use the view toggle to see all 88 keys.
Piano key
45 of 88
Octave
4
Frequency
349.23 Hz
MIDI number
65
Key color
White key
Pitch class
F · E# · Gbb
What is F4?
F4 is the F in octave 4 — the 45th key of the 88 on a full-size piano, counted from the bottom. In standard tuning it sounds at 349.23 Hz. It sits 5 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 698.46 Hz and the one below at 174.62 Hz. The same piano key can be written as F, E#, Gbb depending on the musical context — same sound, different spelling.
Nearby notes
Every F on the keyboard: