F Note Frequency — F1 to F7
F is a fourth above C and usually the first key centre a student meets that contains a flat: F major has one flat, B♭.
Every F on an 88-key piano
Frequencies use equal temperament with A4 = 440 Hz. Range shown: F1 to F7 — 7 of the 88 keys.
| Note | MIDI number | Frequency (Hz) |
|---|---|---|
| F1 | 29 | 43.65 |
| F2 | 41 | 87.31 |
| F3 | 53 | 174.61 |
| F4 | 65 | 349.23 |
| F5 | 77 | 698.46 |
| F6 | 89 | 1396.91 |
| F7 | 101 | 2793.83 |
How the frequency of F is calculated
Modern instruments use twelve-tone equal temperament, where an octave is split into twelve equal semitones. With A4 fixed at 440 Hz, any note’s frequency is:
f = 440 × 2(m − 69) / 12
where m is the MIDI note number. For F4 that is
m = 65, giving 349.23 Hz.
F and its neighbours
Each semitone changes the frequency by a ratio of 21/12 ≈ 1.0595 — about 5.95%. Going up one octave doubles it. So F4 at 349.23 Hz has a neighbour 329.63 Hz a semitone below and 369.99 Hz a semitone above, and F5 at 698.46 Hz an octave above.
Frequently asked questions
- What is the frequency of F4?
- F4 is 349.23 Hz in equal temperament with A4 = 440 Hz. It is MIDI note 65.
- How many F notes are on an 88-key piano?
- An 88-key piano runs from A0 to C8 and contains 7 F notes, from F1 (43.65 Hz) to F7 (2793.83 Hz).
- What MIDI number is F4?
- F4 is MIDI note 65. MIDI note numbers run from 0 (C−1) to 127 (G9), with middle C (C4) at 60 and A4 at 69.
- Why does the frequency double every octave?
- An octave is a 2:1 frequency ratio. In twelve-tone equal temperament the octave is divided into twelve equal steps, so each semitone multiplies the frequency by the twelfth root of two (about 1.0595). Twelve of those steps multiply out to exactly 2.
Last updated: 2026-09-01