F-1
10.913Hz at concert pitch
Press to hear a pure sine tone at this pitch.
MIDI note
5
Piano key
—
Octave
-1
Frequency
10.913 Hz
Period
91.6338 ms
Wavelength
31.4304 m
Pitch class
F
Notation
SPN
MIDI is the note number synths and software pass around (0–127). Pitch class is the note without its octave — all the Fs share one. This note falls outside the 88-key piano, so it has no piano key number.
At other reference pitches
| Reference (A4) | F-1 frequency | Where you meet it |
|---|---|---|
| 432 Hz | 10.715 Hz | the alternative-tuning circle |
| 440 Hzstandard | 10.913 Hz | the ISO 16 standard — concert pitch |
| 442 Hz | 10.963 Hz | many European orchestras tune a touch sharp |
| 443 Hz | 10.988 Hz | some sharper continental orchestras |
Every row is F-1 — only the A4 you tune to changes. A frequency scales straight with the reference: F-1 at 432 Hz is the 440 Hz value times 432⁄440.
Move around
Every F
Chords with F in them
F appears in each of these — see the whole chord grid.