A8 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 | A8 | vs 440 |
|---|---|---|
| A4 = 415 Hz · Baroque pitch | 6640.0 Hz | −101.3¢ |
| A4 = 432 Hz · “Verdi” pitch | 6912.0 Hz | −31.8¢ |
| A4 = 440 Hz · Standard (ISO 16) | 7040.0 Hz | — |
| A4 = 442 Hz · Orchestral | 7072.0 Hz | +7.9¢ |
One cycle of A8 lasts 142.0 µs, and its wavelength in air at 20 °C is 4.9 cm. Hold it as a steady tone in the tone generator.
A8 on the piano
A8 is above the top of an 88-key piano, whose highest key is C8 — 9 semitones higher. Press any key below to compare it with its neighbours.
A8 on the guitar
A8 is above the highest fret of any standard guitar, so a guitar in standard tuning cannot play it.
A8 on the staff
Instruments that can play A8
None of the instruments in our range charts reach A8.
A8 is outside the typical range of all six voice types. Test your own range.
The harmonics of A8
A played A8 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) | 7040.0 Hz | A8 | 0¢ |
| 2 | 14,080 Hz | A9 | 0¢ |
| 3 | 21,120 Hz | E10 | +2.0¢ |
| 4 | 28,160 Hz | A10 | 0¢ |
| 5 | 35,200 Hz | C♯11 | −13.7¢ |
| 6 | 42,240 Hz | E11 | +2.0¢ |
| 7 | 49,280 Hz | G11 | −31.2¢ |
| 8 | 56,320 Hz | A11 | 0¢ |
Frequently asked questions
What is the frequency of A8?
A8 is 7040.0 Hz in equal temperament with A4 tuned to 440 Hz, the international standard. At A4 = 432 Hz it is 6912.0 Hz, and at the orchestral A4 = 442 Hz it is 7072.0 Hz.
Which octave is A8 in?
The number is the octave in scientific pitch notation, where each octave starts on C and C4 is middle C. A8 is in octave 8, 57 semitones above middle C. In Helmholtz notation, used in older books, it is written a′×5.
How do I play A8 on a piano?
A8 is above the top of an 88-key piano, whose highest key is C8 — 9 semitones higher.
Which instruments can play A8?
None of the instruments we chart reach A8; it is outside the range of ordinary instruments.
Typing it? A8 is also written A8. Convert any frequency on the Hz-to-note converter.