7040.0Hz
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7.04 kHzFrequency at A4 = 440 Hz
117MIDI note number
–Piano key (of 88)
4.9 cmWavelength in air
About A8
A8 has a frequency of 7.04 kHz in standard tuning, where A4 is fixed at 440 Hz. It is MIDI note 117, outside the range of a standard piano.
In equal temperament every semitone multiplies the frequency by the twelfth root of two (≈1.05946), so A8 is 48 semitones above A4: f = 440 × 2^((117 − 69) / 12) = 7,040.00 Hz. The number in the name is the octave in scientific pitch notation, which starts each octave on C.
A8 frequency in different tunings
| Tuning reference | A8 frequency |
|---|---|
| A4 = 440 Hz (ISO 16 standard) | 7.04 kHz |
| A4 = 442 Hz (many European orchestras) | 7.072 kHz |
| A4 = 443 Hz (Berlin, Vienna) | 7.088 kHz |
| A4 = 435 Hz (French diapason normal, 1859) | 6.96 kHz |
| A4 = 432 Hz (alternative tuning) | 6.912 kHz |
| A4 = 415 Hz (Baroque pitch) | 6.64 kHz |
| C4 = 256 Hz (scientific pitch) | 6.889 kHz |
Intervals from A8
| Interval | Note | Frequency | Ratio (just) |
|---|---|---|---|
| Minor second | A♯8 | 7.459 kHz | 16:15 |
| Major second | B8 | 7.902 kHz | 9:8 |
| Minor third | C9 | 8.372 kHz | 6:5 |
| Major third | C♯9 | 8.87 kHz | 5:4 |
| Perfect fourth | D9 | 9.397 kHz | 4:3 |
| Tritone | D♯9 | 9.956 kHz | 45:32 |
| Perfect fifth | E9 | 10.548 kHz | 3:2 |
| Minor sixth | F9 | 11.175 kHz | 8:5 |
| Major sixth | F♯9 | 11.84 kHz | 5:3 |
| Minor seventh | G9 | 12.544 kHz | 9:5 |
| Major seventh | G♯9 | 13.29 kHz | 15:8 |
| Octave | A9 | 14.08 kHz | 2:1 |
Frequently asked questions
What is the frequency of A8?
A8 is 7.04 kHz when A4 = 440 Hz (6.912 kHz if A4 = 432 Hz).
What MIDI number is A8?
A8 is MIDI note number 117.
Is A8 on a piano?
No – a standard 88-key piano runs from A0 to C8, so A8 is outside its range.