Concert pitch A4 is internationally standardized at 440.00 Hz (ISO 16:1975). Alternative 432 Hz tuning sits precisely 31.766 cents flat relative to 440 Hz. Musical cents deviation is calculated via c = 1200 * log2(f2 / f1), with ±5 cents defining the psychoacoustic threshold for acceptable instrumental intonation.
c = 1200 × log2(f_detected / f_reference)A chromatic tuner is an essential tool for any musician. Unlike standard tuners that only recognize specific notes (like E-A-D-G-B-E for guitar), a chromatic tuner can detect and display any note in the chromatic scale – all 12 notes from C to B, including sharps and flats. This makes it perfect for tuning any instrument, from guitars and basses to violins, cellos, wind instruments, and even your voice.
Our free online chromatic tuner uses your device's built-in microphone to capture the sound of your instrument. The audio is then analyzed using a sophisticated autocorrelation pitch detection algorithm – the same technology used in professional audio equipment. The tuner identifies the fundamental frequency of the note you're playing and displays:
In music, a "cent" is a unit of measure for pitch. One semitone (the distance from one key to the next on a piano) equals 100 cents. Most musicians consider a note "in tune" when it's within ±5 cents of the target pitch. The human ear typically can't distinguish differences smaller than 5-10 cents, making this an excellent threshold for practical use.
The standard concert pitch used worldwide is A4 = 440Hz. This means the A note above middle C vibrates at 440 cycles per second. However, some musicians prefer A4 = 432Hz, often called "Verdi's A," which some claim produces a warmer, more natural sound. Our tuner supports both references – simply select your preference from the dropdown menu.
Our tuner includes 27+ preset tunings for guitar, bass, orchestral strings, and folk instruments:
Can't use your microphone? Our tuner includes reference tone buttons that play the exact pitch for each string in your selected tuning. Simply listen and match your instrument's pitch to the reference tone – a technique used by musicians for centuries.
Playing an out-of-tune instrument doesn't just sound bad – it can train your ear incorrectly and make ensemble playing impossible. Regular tuning develops your pitch recognition skills, ensures your practice is effective, and shows respect for other musicians and audiences. Whether you're a beginner or professional, staying in tune is fundamental to making great music.
When tuning a guitar, always tune up to the note rather than down. If you overshoot, tune below the target note and come back up. This ensures the string tension is consistent and helps the tuning stay stable longer.
Standard concert pitch defines A4 at 440.00 Hz under modern 12-tone equal temperament. Tuning to 432 Hz introduces an exact -31.76 cent flat offset. Use this crawlable reference table for audio mastering calibration and analog synth calibration.
| Musical Note | Standard A4 = 440 Hz | Verdi Pitch A4 = 432 Hz | Cent Offset | Instrument Application |
|---|---|---|---|---|
| C2 | 65.41 Hz | 64.22 Hz | -31.76¢ | Low Cello / Sub Bass |
| E2 | 82.41 Hz | 80.91 Hz | -31.76¢ | Guitar Low 6th String |
| A2 | 110.00 Hz | 108.00 Hz | -31.76¢ | Guitar 5th String |
| D3 | 146.83 Hz | 144.16 Hz | -31.76¢ | Guitar 4th String / Viola |
| G3 | 196.00 Hz | 192.44 Hz | -31.76¢ | Guitar 3rd String / Violin Low G |
| B3 | 246.94 Hz | 242.45 Hz | -31.76¢ | Guitar 2nd String |
| C4 (Middle C) | 261.63 Hz | 256.87 Hz | -31.76¢ | Piano Middle Reference |
| E4 | 329.63 Hz | 323.63 Hz | -31.76¢ | Guitar 1st High E |
| A4 (Concert Pitch) | 440.00 Hz | 432.00 Hz | -31.76¢ | Orchestral Master Pitch |
| C5 | 523.25 Hz | 513.74 Hz | -31.76¢ | Soprano Vocal Range |
| E5 | 659.25 Hz | 647.27 Hz | -31.76¢ | High Violin E String |
| A5 | 880.00 Hz | 864.00 Hz | -31.76¢ | Flute & High Lead |