A guitar’s open strings are tuned to specific frequencies in standard tuning. From the thickest string to the thinnest, they are E, A, D, G, B, and E again. The frequencies are approximately 82 Hz, 110 Hz, 147 Hz, 196 Hz, 247 Hz, and 330 Hz respectively.
These frequencies are locked to the equal temperament scale, the tuning system used in nearly all modern Western music. This means every open string and every fretted note on a guitar is tuned to an exact Hertz value that keeps the instrument in tune with other instruments and digital audio systems.
Open String Frequencies in Standard Tuning
The low E string (the thickest string, also called the 6th string) vibrates at 82.41 Hz. This is the E note in the music world—specifically, E2, two octaves below middle C.
The A string vibrates at 110 Hz. The D string vibrates at 146.83 Hz. The G string vibrates at 196 Hz. The B string vibrates at 246.94 Hz. The high E string (the thinnest string, or 1st string) vibrates at 329.63 Hz.
These are the baseline frequencies. When you pick an open string, that’s the pitch you get. When you press a string down on a fret, you shorten the vibrating length of the string, which increases its frequency—and therefore its pitch.
How Frets Change Frequency
Each fret on a guitar raises the pitch of a string by exactly one semitone. One semitone represents a frequency ratio of about 1.059—in other words, each fret increases the frequency by roughly 5.9%.
If the low E string is 82.41 Hz, then fretting the first fret (F note) raises it to about 87.31 Hz. The second fret (F#) is about 92.5 Hz. The third fret (G) is about 98 Hz. This continues all the way up the neck.
Because the frequency increases exponentially rather than linearly, the physical distance between frets gets progressively smaller as you move toward the body of the guitar. The first fret is farther from the second fret than the 20th fret is from the 21st fret—even though each raises the pitch by one semitone. This is why guitar necks are designed with a specific radius and fret spacing.
Understanding how frets and frequencies relate helps you tune your guitar accurately. If you know the open string frequency and you know each fret raises it by 5.9%, you can predict the frequency of any note on the neck.
Using Frequencies to Tune a Guitar
Modern tuners work by detecting the frequency of a vibrating string and comparing it to the target frequency. If your low E string is vibrating at 80 Hz instead of 82.41 Hz, the tuner shows you that you’re sharp (too low). You tighten the tuning peg to increase the frequency until it matches exactly.
Many guitarists tune by ear using their ears and muscle memory, but frequency-based tuning (using a tuner) is more accurate and faster. A tuner eliminates guesswork—you can see whether you’re within 1 Hz of the target or off by 5 Hz, and you can adjust accordingly.
Standard guitar tuning frequencies are based on A4 = 440 Hz, the international orchestral tuning standard. If you’re using a tuner that defaults to 440 Hz, your guitar will be in tune with pianos, orchestras, and recorded music at that standard.
Some alternative tunings use different frequencies or relationships between strings. Drop-D tuning, for example, lowers the low E string to D (73.42 Hz) while keeping the other strings standard. Open tunings rearrange the strings to create specific chords. But these are variations on the frequency principle—you’re just changing which frequencies are assigned to which strings.
Harmonic Frequencies on Guitar
When you pluck a guitar string, it doesn’t vibrate at just one frequency. It vibrates at the fundamental frequency (which determines the note) plus multiple overtones—harmonics at higher frequencies like 2x, 3x, 4x the fundamental, and so on.
These harmonics are what give the guitar its characteristic warm, rich tone. A guitar string’s harmonics include some unpleasant frequencies, which is why guitars are designed with specific body shapes, wood types, and internal bracing to dampen those and amplify the pleasant ones.
Natural harmonics on a guitar occur when you lightly touch a string at specific points without pressing it down. These points correspond to fractions of the string length—the 12th fret is halfway along, the 7th fret is one-third, and so on. Touching the string at these spots isolates specific harmonics and creates the characteristic bell-like harmonic tone.
Instruments go out of tune partly because string tension changes over time, which shifts the frequency. Understanding these relationships helps you maintain accurate tuning.
Frequently Asked Questions
What are the exact frequencies of standard guitar tuning?
Standard tuning open strings are E (82.41 Hz), A (110 Hz), D (146.83 Hz), G (196 Hz), B (246.94 Hz), and E (329.63 Hz). These assume the reference pitch A4 = 440 Hz. Different tuning standards (like 432 Hz) would shift all frequencies proportionally.
How much does each fret change the frequency?
Each fret raises the frequency by a ratio of 2^(1/12), or about 5.9%. This means each fret increases the frequency by an amount proportional to the current frequency, not by a fixed number of Hz.
Can I tune my guitar without a tuner using frequencies?
Yes, but it requires a reference frequency and a trained ear. You can use a tuning fork, a piano, or a reference tone (online or from an app) to establish the frequency of one string. Then you can tune the other strings relative to that one by ear, using interval recognition.
Vincent is a pitch detection and vocal analysis writer at OnlinePitchDetector. He focuses on pitch recognition, vocal frequency analysis, singing tools, and real-time audio testing for singers, musicians, producers, and beginners.