Online Tuning Fork
Strike the fork and listen as it rings and fades. Use it as a pure pitch to tune a string or your voice against.
A 440 Hz
Tap the fork to strike it
The international concert pitch. Orchestras tune to it, and so do guitar tuners: the open A string is 110 Hz, two octaves down.
The Forks and What They Are For
| Fork | Frequency | Typical use |
|---|---|---|
| A 440 | 440 Hz | The international concert pitch. Orchestras tune to it, and so do guitar tuners: the open A string is 110 Hz, two octaves down. |
| A 442 | 442 Hz | Slightly sharper, used by many European orchestras and for a brighter string sound. |
| A 432 | 432 Hz | Verdi's A, preferred by some players for its warmer feel. See the 432 Hz tuner. |
| E 329.63 | 329.63 Hz | The high E string of a guitar (E4). Tune the thin string to it, then the rest from that. |
| C 523.25 | 523.25 Hz | Middle C's octave (C5). Common for medical and educational forks, and a handy ear reference. |
| C 256 | 256 Hz | Scientific or 'philosophical' pitch — every C is a power of two. A teaching and acoustics standard. |
How to Tune with a Fork
- Choose a fork and tap it to strike it. It rings for about ten seconds.
- Play the matching string — the A fork with the A string, the E fork with the thin E.
- Listen for beating: a slow pulsing of loudness that means the two pitches differ by a few hertz. The slower the pulse, the closer you are; when it stops, they match.
- Tune the remaining strings from that one using the fifth-fret method, or sound each in turn on the pitch pipe.
Fork or Tuner?
The chromatic tuner shows how many cents sharp or flat a string is. A fork gives you nothing to read; it gives you a clean sound to match, which is slower to learn but builds your ear. Many teachers have students tune by ear to a fork and then check with a tuner. See also the tone generator for any frequency between 20 Hz and 20 kHz.
Frequently Asked Questions
How does a tuning fork work?
A tuning fork is a U-shaped bar of steel. When struck, its two tines swing in and out at a fixed rate, set by their length and stiffness. That produces an almost pure sine wave with very little overtone content, which is why a fork is such a clean reference. A 440 Hz fork vibrates 440 times a second.
How do I tune a guitar with an A440 fork?
Strike the fork and play the open A string, which sounds 110 Hz, two octaves below the fork. The two notes are the same pitch class, so adjust the peg until the beating between them stops. Then tune the other strings from the A using the fifth-fret method: the 5th fret of the low E string is an A, the 5th fret of the A string is a D, and so on.
Why does the sound fade?
A real fork loses energy to the air and to your hand, so the note decays over several seconds. This one rings for about ten, the first brief clang dying almost immediately, as on a steel fork. Tap it again to restrike, or press Damp to stop it at once.
Which fork should I use?
A 440 Hz for almost everything: it is the international standard. Use the E 329.63 Hz fork to tune the thin E string on a guitar. A 442 Hz suits orchestras that tune sharp, and 432 Hz is preferred by some players. C forks are used in teaching and acoustics.
Is this as accurate as a real tuning fork?
The pitch is calculated, so it is exact to the accuracy of your device's audio clock — better than a cheap fork, which can be several cents off and changes slightly with temperature. The tone is a synthetic fork, so it will not match the exact timbre of a steel one, but the pitch is what you tune to.