Convert any frequency in Hz to the nearest musical note, or any note to its frequency. This frequency to note converter shows how many cents the frequency is sharp or flat, its MIDI number and piano key, and which voice types sing it, with standard A4 = 440 Hz tuning or any other reference. The full frequency chart from C0 to B8 is below the converter.
Frequency to Note Converter
Type a frequency to find the nearest note, or pick a note to get its frequency. Works for voices, instruments and any sound from 1 to 20,000 Hz.
- Your frequency
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- Note frequency
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- Cents off
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- MIDI note
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- Piano key
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- Period
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- Wavelength in air
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- Neighbours
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Frequency to note chart (A4 = 440 Hz, values in Hz)
| Note | Octave 0 | Octave 1 | Octave 2 | Octave 3 | Octave 4 | Octave 5 | Octave 6 | Octave 7 | Octave 8 |
|---|---|---|---|---|---|---|---|---|---|
| C | |||||||||
| C♯ / D♭ | |||||||||
| D | |||||||||
| D♯ / E♭ | |||||||||
| E | |||||||||
| F | |||||||||
| F♯ / G♭ | |||||||||
| G | |||||||||
| G♯ / A♭ | |||||||||
| A | |||||||||
| A♯ / B♭ | |||||||||
| B |
Middle C (C4) and A4 are highlighted. Select any frequency to convert it.
12-tone equal temperament. Everything runs in your browser; nothing is uploaded.
How to Convert Hz to a Note
- Type the frequency, for example 220, and press Convert.
- Read the nearest note (A3 for 220 Hz) and how far the frequency is from it in cents.
- Change the tuning if your music uses A4 = 432, 442, 443 or 415 Hz, or enter a custom reference.
- Switch to Note to Hz to go the other way, or select any value in the chart.
Use Copy link to share a result: the link opens the converter with the same frequency or note.
The Formula
In 12-tone equal temperament every semitone multiplies the frequency by the twelfth root of 2 (about 1.0595), so an octave doubles it. The note number is n = 69 + 12 × log₂(f ÷ 440), where 69 is A4 on the MIDI scale. Round n to the nearest whole number to get the note; the difference × 100 is the distance in cents. Going the other way, f = 440 × 2(n − 69) ÷ 12. For example, 100 Hz gives n = 43.35: note 43 is G2 (98.00 Hz), and 0.35 × 100 = +35 cents.
What Note Is That Frequency?
| Frequency | Nearest note | Cents | Exact note frequency |
|---|---|---|---|
| 20 Hz | D♯0 | +49 | 19.45 Hz |
| 60 Hz | B1 | −49 | 61.74 Hz |
| 100 Hz | G2 | +35 | 98.00 Hz |
| 110 Hz | A2 | 0 | 110.00 Hz |
| 128 Hz | C3 | −38 | 130.81 Hz |
| 200 Hz | G3 | +35 | 196.00 Hz |
| 220 Hz | A3 | 0 | 220.00 Hz |
| 256 Hz | C4 | −38 | 261.63 Hz |
| 432 Hz | A4 | −32 | 440.00 Hz |
| 440 Hz | A4 | 0 | 440.00 Hz |
| 500 Hz | B4 | +21 | 493.88 Hz |
| 528 Hz | C5 | +16 | 523.25 Hz |
| 1,000 Hz | B5 | +21 | 987.77 Hz |
Frequencies such as 20 Hz and 60 Hz fall almost exactly between two notes, so a tiny change moves them to the other one. 20 Hz is also the lower limit of human hearing: you feel it more than you hear it. 60 Hz is the hum of mains electricity in North America; in Europe the hum is 50 Hz, close to G1.
Useful Note Frequencies
| Note | Frequency | Why it matters |
|---|---|---|
| A0 | 27.50 Hz | Lowest key on a piano |
| E2 | 82.41 Hz | Low E of a guitar; bottom of a typical bass voice |
| C4 | 261.63 Hz | Middle C |
| A4 | 440.00 Hz | Standard tuning note |
| B4 | 493.88 Hz | The B above middle C |
| C6 | 1,046.50 Hz | Soprano high C |
| C8 | 4,186.01 Hz | Highest key on a piano |
Singing voices mostly live between about 80 Hz and 1,050 Hz: see how each voice type fits into that span in typical vocal ranges. How the voice creates those frequencies is explained in how vocal cords produce pitch.
Frequency Ranges of Voices and Instruments
| Sound | Lowest | Highest |
|---|---|---|
| Bass voice (typical) | E2, 82 Hz | E4, 330 Hz |
| Soprano voice (typical) | C4, 262 Hz | C6, 1,047 Hz |
| Guitar (standard tuning, 22 frets) | E2, 82 Hz | D6, 1,175 Hz |
| Violin | G3, 196 Hz | about E7, 2,637 Hz |
| Piano (88 keys) | A0, 27.5 Hz | C8, 4,186 Hz |
| Human hearing | about 20 Hz | about 20,000 Hz |
These are fundamental frequencies, the pitch you hear. Every voice and instrument also produces overtones far above them, which is why a violin and a flute playing the same A4 still sound different.
Why Low Notes Are Close Together in Hz
Because each semitone multiplies the frequency by the same factor, the gap in hertz grows as notes get higher. From A1 (55 Hz) to A♯1 is only 3.3 Hz, but from A5 (880 Hz) to A♯5 is 52.3 Hz. That is why a small error in a low frequency can change the note name, and why the converter shows cents: cents measure the same musical distance at every height. A difference of 5 cents is inaudible to most listeners; by 20 to 25 cents most people hear a note as out of tune.
A4 = 440 Hz or 432 Hz?
Almost all modern music is tuned to A4 = 440 Hz, the international standard since 1955. Some orchestras tune slightly higher (442 or 443 Hz) for a brighter sound, Baroque ensembles often use 415 Hz, and some musicians prefer 432 Hz. Changing the reference changes every note’s frequency: with A4 = 432 Hz, middle C is 256.87 Hz instead of 261.63 Hz. The chart and results update when you change the tuning.
What the Other Results Mean
- MIDI note: the number used by keyboards and music software; middle C is 60 and A4 is 69.
- Piano key: the key number on an 88-key piano, from A0 (1) to C8 (88).
- Period: the length of one vibration; 440 Hz repeats every 2.27 ms.
- Wavelength in air: the length of one sound wave at 343 m/s; A4 is about 78 cm long.
- Neighbours: the notes a semitone below and above, to see how close the frequency is to each.
Convert Your Own Voice or an Instrument
If you don’t know the frequency yet, measure it: the pitch detector shows the live frequency and note of any sound, and the note detector names every note in a recording. To find the average frequency of your speaking voice, take the voice Hz test. To find your singing range and voice type from your lowest and highest notes, use the vocal range calculator.
For more maths between notes, the octave calculator works out octaves between frequencies, and the semitone calculator counts semitones between notes.
Frequently Asked Questions
What note is 440 Hz?
A4, the A above middle C: the standard tuning note.
What frequency is B4?
493.88 Hz with A4 = 440 Hz.
What frequency is middle C?
261.63 Hz (C4) in standard tuning, or 256.87 Hz with A4 = 432 Hz.
What note is 432 Hz?
With standard tuning, 432 Hz is an A4 that is 32 cents flat. With A4 = 432 Hz tuning it is exactly A4.
How do I convert Hz to a note without a calculator?
Find the nearest value in the chart above. Each row is a note name and each column an octave.