Note Frequency Chart
The frequency of every note in hertz, from C0 to B8. Change the concert pitch and every value updates; tap a note to hear it.
| Note | Octave 0 | Octave 1 | Octave 2 | Octave 3 | Octave 4 | Octave 5 | Octave 6 | Octave 7 | Octave 8 |
|---|---|---|---|---|---|---|---|---|---|
| C | |||||||||
| C♯/D♭ | |||||||||
| D | |||||||||
| D♯/E♭ | |||||||||
| E | |||||||||
| F | |||||||||
| F♯/G♭ | |||||||||
| G | |||||||||
| G♯/A♭ | |||||||||
| A | |||||||||
| A♯/B♭ | |||||||||
| B |
Frequencies in hertz at A4 = 440 Hz, equal temperament. Tap any value to hear it. Highlighted: A4, the tuning reference. Underlined: the six open strings of a guitar in standard tuning.
Frequency to note
is G3 · wavelength 175.0 cm
How Note Frequencies Work
A note's frequency is how many times per second the sound wave repeats, measured in hertz (Hz). Modern Western music fixes one reference — A4, the A above middle C, at 440 Hz — and divides every octave into twelve equal semitones. Moving up a semitone multiplies the frequency by 21/12, about 1.0595. Twelve of those steps exactly double it, which is why A5 is 880 Hz, A3 is 220 Hz and A2 is 110 Hz.
The formula for any note is f = 440 × 2n/12, where n is the number of semitones from A4. The chart above is generated from exactly that formula, so changing the concert pitch moves every value by the same ratio.
Guitar String Frequencies
The six open strings of a guitar in standard tuning are underlined in the chart. Here they are on their own, at A4 = 440 Hz:
| String | Note | Frequency |
|---|---|---|
| 6 (low E) | E2 | 82.41 Hz |
| 5 (A) | A2 | 110.00 Hz |
| 4 (D) | D3 | 146.83 Hz |
| 3 (G) | G3 | 196.00 Hz |
| 2 (B) | B3 | 246.94 Hz |
| 1 (high E) | E4 | 329.63 Hz |
The high E string is exactly two octaves above the low E — four times its frequency. The guitar tunings chart lists every string in every alternate tuning, and each tuner on this site listens for these exact numbers.
Using the Chart
- Tuning and reference. Tap a note to hear it as a plucked tone, or open the tone generator for a steady sine wave at any frequency.
- Mixing and EQ.Knowing that a bass guitar's low E is 41 Hz and a kick drum's thump sits nearby tells you where the two will fight, and where to cut.
- Identifying a frequency.Type any frequency into the converter below the chart to get the nearest note and how many cents it is off — useful for reading spectrum analysers or hum. Mains hum at 50 Hz, for example, sits between G1 and G♯1, and 60 Hz hum almost exactly halfway between A♯1 and B1.
- Alternate concert pitches.Orchestras in Europe often tune to 442 or 443 Hz, baroque ensembles to around 415 Hz, and some players prefer 432 Hz. Pick one above and every frequency updates.
Cents: Measuring Small Differences
Musicians measure small pitch differences in cents: one hundredth of a semitone. Because a semitone is a ratio rather than a fixed number of hertz, a cent is about 0.05 Hz at the low E string but about 0.25 Hz at A4. That is why tuners show cents rather than hertz — a string 5 cents flat sounds equally out of tune wherever it is. Most people notice 5 to 10 cents; the guitar tuner reads to a fraction of a cent.
Frequently Asked Questions
What is the frequency of middle C?
261.63 Hz at standard concert pitch (A4 = 440 Hz). Middle C is C4 in scientific pitch notation. At A4 = 432 Hz it drops to about 256.87 Hz.
How do I calculate the frequency of a note?
Count the semitones n from A4 (negative below it, positive above) and use f = 440 × 2^(n/12). Each semitone multiplies the frequency by the twelfth root of two, about 1.0595, so twelve semitones exactly double it. C4 is 9 semitones below A4: 440 × 2^(−9/12) = 261.63 Hz.
Why is A4 the reference note?
It is the note orchestras tune to and the one tuning forks are made for. The value 440 Hz was standardised internationally in the 20th century; before that, A ranged from roughly 415 to over 450 Hz depending on the time and place. Everything in the chart is calculated from whichever A4 you choose.
What do the octave numbers mean?
Scientific pitch notation numbers each octave from C. C4 is middle C; the B just below it is B3, and the C above B4 is C5. A piano runs from A0 to C8, and a guitar in standard tuning from E2 to about E6 at the top of a 24-fret neck.
Are these frequencies exact?
They are exact for twelve-tone equal temperament, the tuning used by guitars, pianos and almost all modern instruments, rounded to two decimal places. Other temperaments, such as just intonation, shift some notes by a few cents; real instruments also add overtones above the fundamental listed here.
What does the wavelength mean?
It is how far one cycle of the sound wave travels in air at 20 °C, where sound moves at 343 metres per second. A low E string's wave is about 4.2 metres long; the A above middle C is about 78 cm. It matters for room acoustics and speaker design more than for playing.