G Note Frequency — G1 to G7
G is a fifth above C and typically the second key a student learns — G major carries a single sharp, F♯. The G chord is a staple of folk, country and rock guitar.
Every G on an 88-key piano
Frequencies use equal temperament with A4 = 440 Hz. Range shown: G1 to G7 — 7 of the 88 keys.
| Note | MIDI number | Frequency (Hz) |
|---|---|---|
| G1 | 31 | 49.00 |
| G2 | 43 | 98.00 |
| G3 | 55 | 196.00 |
| G4 | 67 | 392.00 |
| G5 | 79 | 783.99 |
| G6 | 91 | 1567.98 |
| G7 | 103 | 3135.96 |
How the frequency of G 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 G4 that is
m = 67, giving 392.00 Hz.
G 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 G4 at 392.00 Hz has a neighbour 369.99 Hz a semitone below and 415.30 Hz a semitone above, and G5 at 783.99 Hz an octave above.
Frequently asked questions
- What is the frequency of G4?
- G4 is 392.00 Hz in equal temperament with A4 = 440 Hz. It is MIDI note 67.
- How many G notes are on an 88-key piano?
- An 88-key piano runs from A0 to C8 and contains 7 G notes, from G1 (49.00 Hz) to G7 (3135.96 Hz).
- What MIDI number is G4?
- G4 is MIDI note 67. 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