3520.0Hz
Start with your device volume low. Very low tones may be inaudible on phone or laptop speakers; very high tones can be uncomfortable on headphones.
3.52 kHzFrequency at A4 = 440 Hz
105MIDI note number
85Piano key (of 88)
9.7 cmWavelength in air
About A7
A7 has a frequency of 3.52 kHz in standard tuning, where A4 is fixed at 440 Hz. It is MIDI note 105 and key number 85 on an 88-key piano.
In equal temperament every semitone multiplies the frequency by the twelfth root of two (≈1.05946), so A7 is 36 semitones above A4: f = 440 × 2^((105 − 69) / 12) = 3,520.00 Hz. The number in the name is the octave in scientific pitch notation, which starts each octave on C.
A7 frequency in different tunings
| Tuning reference | A7 frequency |
|---|---|
| A4 = 440 Hz (ISO 16 standard) | 3.52 kHz |
| A4 = 442 Hz (many European orchestras) | 3.536 kHz |
| A4 = 443 Hz (Berlin, Vienna) | 3.544 kHz |
| A4 = 435 Hz (French diapason normal, 1859) | 3.48 kHz |
| A4 = 432 Hz (alternative tuning) | 3.456 kHz |
| A4 = 415 Hz (Baroque pitch) | 3.32 kHz |
| C4 = 256 Hz (scientific pitch) | 3.444 kHz |
Intervals from A7
| Interval | Note | Frequency | Ratio (just) |
|---|---|---|---|
| Minor second | A♯7 | 3.729 kHz | 16:15 |
| Major second | B7 | 3.951 kHz | 9:8 |
| Minor third | C8 | 4.186 kHz | 6:5 |
| Major third | C♯8 | 4.435 kHz | 5:4 |
| Perfect fourth | D8 | 4.699 kHz | 4:3 |
| Tritone | D♯8 | 4.978 kHz | 45:32 |
| Perfect fifth | E8 | 5.274 kHz | 3:2 |
| Minor sixth | F8 | 5.588 kHz | 8:5 |
| Major sixth | F♯8 | 5.92 kHz | 5:3 |
| Minor seventh | G8 | 6.272 kHz | 9:5 |
| Major seventh | G♯8 | 6.645 kHz | 15:8 |
| Octave | A8 | 7.04 kHz | 2:1 |
Instruments and voices that can play A7
Frequently asked questions
What is the frequency of A7?
A7 is 3.52 kHz when A4 = 440 Hz (3.456 kHz if A4 = 432 Hz).
What MIDI number is A7?
A7 is MIDI note number 105.
Is A7 on a piano?
Yes – it is key 85 of 88.