C6 at every common reference pitch
A note’s frequency depends on what A4 is tuned to. The standard is 440 Hz; the other three are the ones you are most likely to meet. The cents column is how far each one sits from the 440 version — the same for every note, because changing the reference moves the whole scale together.
| Reference | C6 | vs 440 |
|---|---|---|
| A4 = 415 Hz · Baroque pitch | 987.04 Hz | −101.3¢ |
| A4 = 432 Hz · “Verdi” pitch | 1027.5 Hz | −31.8¢ |
| A4 = 440 Hz · Standard (ISO 16) | 1046.5 Hz | — |
| A4 = 442 Hz · Orchestral | 1051.3 Hz | +7.9¢ |
One cycle of C6 lasts 955.6 µs, and its wavelength in air at 20 °C is 32.8 cm. Hold it as a steady tone in the tone generator.
C6 on the piano
C6 is key 64 of 88, counting from the bottom — a white key. Press any key below to compare it with its neighbours.
C6 on the guitar
C6 is above the 19th fret, the top of a classical guitar; on an electric with more frets it is the 1st string at fret 20.
C6 on the staff
Instruments that can play C6
31 instruments play C6 within the normal range, and 5 reach it only at the extreme of theirs. Each links to its range chart; for a transposing instrument, the note on its part is shown.
Guitars and basses
Plucked and struck strings
Woodwind
Only at the extreme of their range
Voices: C6 is inside the typical range of the soprano. Test your own range.
The harmonics of C6
A played C6 is not one frequency. A string or a pipe also sounds whole-number multiples of it, and the mix of those harmonics is the instrument’s tone. Here is where the first eight land — and why the 7th sounds out of tune against a piano.
| Harmonic | Frequency | Nearest note | Off by |
|---|---|---|---|
| 1 (fundamental) | 1046.5 Hz | C6 | 0¢ |
| 2 | 2093.0 Hz | C7 | 0¢ |
| 3 | 3139.5 Hz | G7 | +2.0¢ |
| 4 | 4186.0 Hz | C8 | 0¢ |
| 5 | 5232.5 Hz | E8 | −13.7¢ |
| 6 | 6279.0 Hz | G8 | +2.0¢ |
| 7 | 7325.5 Hz | B♭8 | −31.2¢ |
| 8 | 8372.0 Hz | C9 | 0¢ |
Frequently asked questions
What is the frequency of C6?
C6 is 1046.5 Hz in equal temperament with A4 tuned to 440 Hz, the international standard. At A4 = 432 Hz it is 1027.5 Hz, and at the orchestral A4 = 442 Hz it is 1051.3 Hz.
Which octave is C6 in?
The number is the octave in scientific pitch notation, where each octave starts on C and C4 is middle C. C6 is in octave 6, 24 semitones above middle C. In Helmholtz notation, used in older books, it is written c‴.
How do I play C6 on a piano?
C6 is key 64 of 88, counting from the bottom — a white key.
Which instruments can play C6?
31 of the instruments we chart play C6 within their normal range, including violin, viola, cello, erhu, 7-string guitar, and 5 more reach it only at the extreme of their range.
Typing it? C6 is also written C6. Convert any frequency on the Hz-to-note converter.