E Note Frequency — E1 to E7
E is both the lowest and the highest open string on a guitar in standard tuning (E2 and E4). It is the tonic of E major and E minor, two core guitar keys.
Every E on an 88-key piano
Frequencies use equal temperament with A4 = 440 Hz. Range shown: E1 to E7 — 7 of the 88 keys.
| Note | MIDI number | Frequency (Hz) |
|---|---|---|
| E1 | 28 | 41.20 |
| E2 | 40 | 82.41 |
| E3 | 52 | 164.81 |
| E4 | 64 | 329.63 |
| E5 | 76 | 659.26 |
| E6 | 88 | 1318.51 |
| E7 | 100 | 2637.02 |
How the frequency of E 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 E4 that is
m = 64, giving 329.63 Hz.
E 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 E4 at 329.63 Hz has a neighbour 311.13 Hz a semitone below and 349.23 Hz a semitone above, and E5 at 659.26 Hz an octave above.
Frequently asked questions
- What is the frequency of E4?
- E4 is 329.63 Hz in equal temperament with A4 = 440 Hz. It is MIDI note 64.
- How many E notes are on an 88-key piano?
- An 88-key piano runs from A0 to C8 and contains 7 E notes, from E1 (41.20 Hz) to E7 (2637.02 Hz).
- What MIDI number is E4?
- E4 is MIDI note 64. 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