B5 Frequency in Hz

B5 is 987.77 Hz in twelve tone equal temperament with A4 at the standard 440 Hz. It is MIDI note 83, piano key 63 of 88, and its wavelength in room-temperature air is about 0.35 m.

Frequency
987.77Hz
MIDI note
83
Piano key
63

B5 sits in the soprano register, the bright end of a violin, flute or female voice. Every number on this page is calculated from one formula rather than copied from a table, so the values here agree exactly with the full note frequency chart and with what the chromatic tuner reads back from your microphone.

How is the frequency of B5 calculated?

Twelve tone equal temperament divides the octave into twelve equal ratios. Each semitone multiplies the frequency by the twelfth root of two, about 1.059463, so twelve semitones multiply it by exactly two and you land one octave higher. Fix one note as the anchor and the rest follow. The anchor is A4, and the modern standard puts it at 440 Hz, which is what ISO 16 specifies as the standard tuning frequency.

Written as a formula, the frequency of MIDI note m is 440 x 2^((m - 69) / 12), because A4 is MIDI note 69. For B5 that is 440 x 2^((83 - 69) / 12) = 440 x 2^(1.1667) = 987.77 Hz. That is 14 semitones above the reference.

What is B5 at other tuning references?

A4 at 440 Hz is the standard, not a law. Historical pitch was lower, and plenty of modern ensembles tune a little higher because a raised pitch is often described as sounding brighter in a large hall. Rebasing the same formula gives these values for B5.

Reference A4B5 in HzDifferenceContext
415 Hz931.64-56.12 HzBaroque pitch, roughly a semitone below modern A
432 Hz969.81-17.96 HzAlternative tuning used by some players, not a standard
435 Hz976.54-11.22 HzDiapason normal, the 19th century French standard
440 Hz987.77referenceModern concert pitch, the ISO 16 standard
442 Hz992.26+4.49 HzCommon in many central European orchestras
443 Hz994.50+6.73 HzUsed by some ensembles that want a brighter sound

Changing the reference multiplies every note by the same ratio, so intervals stay identical and only the absolute pitch moves.

What is B5 in every octave?

Moving up an octave doubles the frequency and moving down halves it, which is the one relationship in tuning that needs no calculator. Here is B across the full chart range.

NoteHzMIDIPiano key
B030.87233
B161.743515
B2123.474727
B3246.945939
B4493.887151
B5987.778363
B61975.59575
B73951.110787
B87902.1119-

What are the harmonics of B5?

A real instrument playing B5 does not produce 987.77 Hz alone. It produces a fundamental plus a series of whole-number multiples, and the balance between them is what makes a violin sound different from a flute on the same note. The harmonics land close to familiar notes but not exactly on them, because the harmonic series is built on simple ratios while equal temperament is not.

HarmonicHzNearest noteCents off
1 (fundamental)987.77B50
21975.5B60
32963.3F#7+2
43951.1B70
54938.8D#8-14
65926.6F#8+2
76914.4A8-31
87902.1B80

The seventh harmonic is the famous outlier: it lands roughly 31 cents flat of the nearest equal-tempered note, which is why it sounds bluesy rather than in tune.

How do I tune to B5?

Play the note and watch the cents readout rather than the hertz readout, because cents are proportional and hertz are not. A tuner rounds to the nearest note, so anything from 959.65 Hz to 1016.7 Hz is read as B5: that is the band fifty cents either side. Most players aim to land inside five cents, which for B5 is roughly 984.92 Hz to 990.62 Hz.

Use the tone generator to play 987.77 Hz as a reference and match it by ear, or open the chromatic tuner and let your microphone do the measuring. Its neighbours are A#5 at 932.33 Hz below and C6 at 1046.5 Hz above, one semitone in each direction.

What intervals are built on B5?

Interval above B5NoteHzRatio
Minor thirdD61174.71.1892
Major thirdD#61244.51.2599
Perfect fourthE61318.51.3348
Perfect fifthF#61480.01.4983
OctaveB61975.52.0000

Ratios are the equal-tempered values. Pure just intonation would put the perfect fifth at exactly 1.5 and the major third at 1.25, which is why equal temperament thirds sound slightly wide.

What is the wavelength of B5?

Sound travels at roughly 343 m/s in dry air at 20 degrees Celsius, so a 987.77 Hz wave is about 0.347 m long, or 34.7 cm. That matters for room acoustics: a wavelength that fits neatly between two parallel walls builds a standing wave, and it is also why a pipe or string producing B5 has the physical length it does. The speed of sound changes with temperature, so treat the figure as a good approximation rather than a constant.

Frequently asked questions

What is the frequency of B5 in Hz?

B5 is 987.77 Hz in twelve tone equal temperament with A4 set to the standard 440 Hz. The value comes from the formula 440 x 2^((m - 69) / 12), where m is the MIDI note number, which is 83 for B5.

What MIDI note number is B5?

B5 is MIDI note 83 when middle C is written C4, the scientific pitch notation used on this site. Software that follows the Yamaha convention labels the same MIDI number B4, one octave lower in name only. The pitch you hear is identical either way.

How far apart are B5 and the note a semitone above it?

One semitone up from B5 is 1046.5 Hz, a difference of 58.74 Hz. Every semitone is the same ratio, the twelfth root of two or about 1.059463, so the gap in hertz grows as you move higher up the keyboard.

What is B5 at A4 = 442 Hz?

Rebasing the same formula on 442 Hz gives 992.26 Hz for B5, about 4.49 Hz higher than the 440 Hz value. Raising the reference shifts every note by the identical ratio, roughly 7.85 cents from 440 to 442.

Where is B5 on a piano?

B5 is key 63 of the 88 keys, counting from A0 at the far left. It is a white key and sits in the soprano register, the bright end of a violin, flute or female voice.

Other notes in octave 5

Music tools that use this frequency