Note Frequency Chart
Every note from C0 to B8 in hertz — with the open guitar and bass strings highlighted, and a reference-pitch control for A4 ≠ 440 setups.
| Note | Oct 0 | Oct 1 | Oct 2 | Oct 3 | Oct 4 | Oct 5 | Oct 6 | Oct 7 | Oct 8 |
|---|---|---|---|---|---|---|---|---|---|
| C | 16.352 | 32.703 | 65.406 | 130.81 | 261.63 | 523.25 | 1046.5 | 2093.0 | 4186.0 |
| C# | 17.324 | 34.648 | 69.296 | 138.59 | 277.18 | 554.37 | 1108.7 | 2217.5 | 4434.9 |
| D | 18.354 | 36.708 | 73.416 | 146.83 | 293.66 | 587.33 | 1174.7 | 2349.3 | 4698.6 |
| D# | 19.445 | 38.891 | 77.782 | 155.56 | 311.13 | 622.25 | 1244.5 | 2489.0 | 4978.0 |
| E | 20.602 | 41.203 | 82.407 | 164.81 | 329.63 | 659.26 | 1318.5 | 2637.0 | 5274.0 |
| F | 21.827 | 43.654 | 87.307 | 174.61 | 349.23 | 698.46 | 1396.9 | 2793.8 | 5587.7 |
| F# | 23.125 | 46.249 | 92.499 | 185.00 | 369.99 | 739.99 | 1480.0 | 2960.0 | 5919.9 |
| G | 24.500 | 48.999 | 97.999 | 196.00 | 392.00 | 783.99 | 1568.0 | 3136.0 | 6271.9 |
| G# | 25.957 | 51.913 | 103.83 | 207.65 | 415.30 | 830.61 | 1661.2 | 3322.4 | 6644.9 |
| A | 27.500 | 55.000 | 110.00 | 220.00 | 440.00 | 880.00 | 1760.0 | 3520.0 | 7040.0 |
| A# | 29.135 | 58.270 | 116.54 | 233.08 | 466.16 | 932.33 | 1864.7 | 3729.3 | 7458.6 |
| B | 30.868 | 61.735 | 123.47 | 246.94 | 493.88 | 987.77 | 1975.5 | 3951.1 | 7902.1 |
cyan = open guitar strings (E2 A2 D3 G3 B3 E4) · violet = open bass strings (E1 A1 D2 G2) · magenta = the A4 reference. Each octave doubles the frequency; each semitone multiplies it by 2^(1/12) ≈ 1.0595.
Reading the chart
Notes are named letter + octave: A4 is the A above middle C (C4). Each column doubles the previous one — that's what an octave is physically. And each step down a row multiplies by 21/12, the equal-temperament semitone, which is why every fret on a guitar is the same ratio apart but a different number of hertz.
Where the guitar lives
The six cyan cells are your open strings. Notice how low the guitar really is — the low E2 at 82 Hz sits just above a cello's lowest C (65 Hz). If you're chasing why notes repeat all over the neck, the fretboard note map lights every position of any note, colored by octave.
These numbers are exactly what the free microphone tuner listens for — tune by mic with a precision needle, or by ear with reference tones.
Open the tunerFrequently asked
What frequency is each guitar string?
In standard tuning with A4 = 440 Hz: low E2 = 82.41 Hz, A2 = 110 Hz, D3 = 146.83 Hz, G3 = 196 Hz, B3 = 246.94 Hz, high E4 = 329.63 Hz. Bass strings are one octave below the guitar's lowest four: E1 ≈ 41.2, A1 = 55, D2 ≈ 73.4, G2 = 98 Hz.
Why is A4 440 Hz?
It's the modern international standard for concert pitch, set in the 20th century. Orchestras historically varied (and some still tune to 442–443 Hz); '432 Hz tuning' is the same math with a lower anchor. The chart's ± buttons recalculate every note from whatever reference you pick.
How are note frequencies calculated?
In equal temperament each semitone multiplies frequency by the 12th root of 2 (≈1.05946), so f = 440 × 2^((n − 69) ÷ 12), where n is the note's MIDI number. Each octave exactly doubles: A3 = 220, A4 = 440, A5 = 880.
What frequency range does a guitar cover?
A 24-fret guitar in standard tuning runs from E2 (82.4 Hz) to E6 (1318.5 Hz) — about four octaves. The harmonics extend far higher, which is why guitar tone has energy well beyond those fundamentals.