3951.07Hz
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3.951 kHzFrequency at A4 = 440 Hz
107MIDI note number
87Piano key (of 88)
8.7 cmWavelength in air
About B7
B7 has a frequency of 3.951 kHz in standard tuning, where A4 is fixed at 440 Hz. It is MIDI note 107 and key number 87 on an 88-key piano.
In equal temperament every semitone multiplies the frequency by the twelfth root of two (≈1.05946), so B7 is 38 semitones above A4: f = 440 × 2^((107 − 69) / 12) = 3,951.07 Hz. The number in the name is the octave in scientific pitch notation, which starts each octave on C.
B7 frequency in different tunings
| Tuning reference | B7 frequency |
|---|---|
| A4 = 440 Hz (ISO 16 standard) | 3.951 kHz |
| A4 = 442 Hz (many European orchestras) | 3.969 kHz |
| A4 = 443 Hz (Berlin, Vienna) | 3.978 kHz |
| A4 = 435 Hz (French diapason normal, 1859) | 3.906 kHz |
| A4 = 432 Hz (alternative tuning) | 3.879 kHz |
| A4 = 415 Hz (Baroque pitch) | 3.727 kHz |
| C4 = 256 Hz (scientific pitch) | 3.866 kHz |
Intervals from B7
| Interval | Note | Frequency | Ratio (just) |
|---|---|---|---|
| Minor second | C8 | 4.186 kHz | 16:15 |
| Major second | C♯8 | 4.435 kHz | 9:8 |
| Minor third | D8 | 4.699 kHz | 6:5 |
| Major third | D♯8 | 4.978 kHz | 5:4 |
| Perfect fourth | E8 | 5.274 kHz | 4:3 |
| Tritone | F8 | 5.588 kHz | 45:32 |
| Perfect fifth | F♯8 | 5.92 kHz | 3:2 |
| Minor sixth | G8 | 6.272 kHz | 8:5 |
| Major sixth | G♯8 | 6.645 kHz | 5:3 |
| Minor seventh | A8 | 7.04 kHz | 9:5 |
| Major seventh | A♯8 | 7.459 kHz | 15:8 |
| Octave | B8 | 7.902 kHz | 2:1 |
Instruments and voices that can play B7
Frequently asked questions
What is the frequency of B7?
B7 is 3.951 kHz when A4 = 440 Hz (3.879 kHz if A4 = 432 Hz).
What MIDI number is B7?
B7 is MIDI note number 107.
Is B7 on a piano?
Yes – it is key 87 of 88.