Online Tuning Fork
Tap A to hear a 440 Hz reference tone, the note orchestras tune to. Change the A4 value to hear 415, 432 or 442 Hz.
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Press Start and play a note
Uses your microphone. Audio stays on your device.
What is A440?
A440 is the A above middle C, vibrating 440 times a second. It is the international standard pitch (ISO 16) and the note most tuning forks produce. Orchestras tune to it, usually played by the oboe.
How to tune with a reference tone
Play the reference A and your A string together. If you hear a slow wobble (beating) the two are slightly apart. Adjust until the wobble disappears. Then tune the other strings from your A.
Other reference pitches
| A4 value | Used for |
|---|---|
| 415 Hz | Baroque pitch, about a semitone below modern |
| 440 Hz | International standard |
| 441 to 442 Hz | Many orchestras, for a slightly brighter sound |
Type the value into the A4 box, then tap the A button.
Frequently asked questions
What frequency is a standard tuning fork?
Most are A440, which is 440 Hz. C523.25 forks are also made for some choirs and piano tuners.