C♯0 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 | C♯0 | vs 440 |
|---|---|---|
| A4 = 415 Hz · Baroque pitch | 16.34 Hz | −101.3¢ |
| A4 = 432 Hz · “Verdi” pitch | 17.01 Hz | −31.8¢ |
| A4 = 440 Hz · Standard (ISO 16) | 17.32 Hz | — |
| A4 = 442 Hz · Orchestral | 17.40 Hz | +7.9¢ |
One cycle of C♯0 lasts 57.724 ms, and its wavelength in air at 20 °C is 19.80 m. Hold it as a steady tone in the tone generator.
C♯0 on the piano
C♯0 is below the bottom of an 88-key piano, whose lowest key is A0 — 8 semitones lower than that. Press any key below to compare it with its neighbours.
C♯0 on the guitar
C♯0 is below the guitar’s lowest note, the open low E (E2), so a guitar in standard tuning cannot play it.
C♯0 on the staff
Instruments that can play C♯0
None of the instruments in our range charts reach C♯0.
C♯0 is outside the typical range of all six voice types. Test your own range.
The harmonics of C♯0
A played C♯0 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) | 17.32 Hz | C♯0 | 0¢ |
| 2 | 34.65 Hz | C♯1 | 0¢ |
| 3 | 51.97 Hz | A♭1 | +2.0¢ |
| 4 | 69.30 Hz | C♯2 | 0¢ |
| 5 | 86.62 Hz | F2 | −13.7¢ |
| 6 | 103.94 Hz | A♭2 | +2.0¢ |
| 7 | 121.27 Hz | B2 | −31.2¢ |
| 8 | 138.59 Hz | C♯3 | 0¢ |
Frequently asked questions
What is the frequency of C♯0?
C♯0 is 17.32 Hz in equal temperament with A4 tuned to 440 Hz, the international standard. At A4 = 432 Hz it is 17.01 Hz, and at the orchestral A4 = 442 Hz it is 17.40 Hz.
Is C♯0 the same note as D♭0?
On a piano, a guitar or a tuner, yes: C♯0 and D♭0 are the same key and the same frequency, 17.32 Hz, in equal temperament. They are two names for one pitch (enharmonic equivalents). Which one is written depends on the key — sharps in sharp keys, flats in flat keys — and a string or wind player may pitch them a few cents apart when playing in just intonation.
How do I play C♯0 on a piano?
C♯0 is below the bottom of an 88-key piano, whose lowest key is A0 — 8 semitones lower than that.
Which instruments can play C♯0?
None of the instruments we chart reach C♯0; it is outside the range of ordinary instruments.
Typing it? C♯0 is also written C#0 or Db0. Convert any frequency on the Hz-to-note converter.