Frequency to note converter and note frequency chart
Notes are written like E2, F#3 or Bb1. Click any number in the chart below to hear it and load it here.
A note's frequency is 440 × 2(n − 69) / 12, where n is its MIDI number. Going the other way, the cents between any frequency and a note are 1200 × log₂(f ÷ note). A4 is 440 Hz, middle C (C4) is 261.63 Hz.
Note frequency chart
| Note | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 |
|---|---|---|---|---|---|---|---|---|---|
| C | 16.35 | 32.70 | 65.41 | 130.81 | 261.63 | 523.25 | 1,046.50 | 2,093.00 | 4,186.01 |
| C♯/D♭ | 17.32 | 34.65 | 69.30 | 138.59 | 277.18 | 554.37 | 1,108.73 | 2,217.46 | 4,434.92 |
| D | 18.35 | 36.71 | 73.42 | 146.83 | 293.66 | 587.33 | 1,174.66 | 2,349.32 | 4,698.64 |
| D♯/E♭ | 19.45 | 38.89 | 77.78 | 155.56 | 311.13 | 622.25 | 1,244.51 | 2,489.02 | 4,978.03 |
| E | 20.60 | 41.20 | 82.41 | 164.81 | 329.63 | 659.26 | 1,318.51 | 2,637.02 | 5,274.04 |
| F | 21.83 | 43.65 | 87.31 | 174.61 | 349.23 | 698.46 | 1,396.91 | 2,793.83 | 5,587.65 |
| F♯/G♭ | 23.12 | 46.25 | 92.50 | 185.00 | 369.99 | 739.99 | 1,479.98 | 2,959.96 | 5,919.91 |
| G | 24.50 | 49.00 | 98.00 | 196.00 | 392.00 | 783.99 | 1,567.98 | 3,135.96 | 6,271.93 |
| G♯/A♭ | 25.96 | 51.91 | 103.83 | 207.65 | 415.30 | 830.61 | 1,661.22 | 3,322.44 | 6,644.88 |
| A | 27.50 | 55.00 | 110.00 | 220.00 | 440.00 | 880.00 | 1,760.00 | 3,520.00 | 7,040.00 |
| A♯/B♭ | 29.14 | 58.27 | 116.54 | 233.08 | 466.16 | 932.33 | 1,864.66 | 3,729.31 | 7,458.62 |
| B | 30.87 | 61.74 | 123.47 | 246.94 | 493.88 | 987.77 | 1,975.53 | 3,951.07 | 7,902.13 |
Frequencies worth knowing
| Middle C (C4) | 261.63 Hz | MIDI note 60 |
| A4, the tuning reference | 440.00 Hz | MIDI note 69 |
| Lowest piano key (A0) | 27.50 Hz | MIDI 21 |
| Highest piano key (C8) | 4,186.01 Hz | MIDI 108 |
| Guitar low E (E2) | 82.41 Hz | standard tuning |
| Bass low E (E1) | 41.20 Hz | 4-string standard |
| 5-string bass low B (B0) | 30.87 Hz | |
| 60 Hz mains hum | B1 -49 cents | US, Canada, parts of Asia |
| 50 Hz mains hum | G1 +35 cents | UK, Europe, most of the world |
| 432 Hz | A4 -31.8 cents | A4 tuned down |
The mains hum rows are why a 60 Hz buzz clashes with a song in B♭ or B, and a 50 Hz one with a song in G. If a hum lives under your track, a narrow cut at the hum frequency and its first few multiples is the usual fix.
Cents, octaves and naming
- A cent is a hundredth of a semitone. Most people stop hearing a difference somewhere around 5 cents on a held note, and tuners call ±2 to ±5 cents in tune.
- An octave doubles the frequency. A3 is 220 Hz, A4 is 440, A5 is 880.
- Octave numbers here are scientific pitch notation, where middle C is C4. Some DAWs, including Ableton Live and Logic Pro, label MIDI note 60 as C3, so their octave numbers read one lower. The frequency is the same; only the label moves.
- Wavelength is the speed of sound (343 m/s) divided by the frequency. Low notes are physically huge: E1 on a bass is about 8.3 m long, which is why small rooms struggle with low end.
Cafecito is free and lives in your DAW.
A chromatic tuner, a Pomodoro timer, notes, to-dos and a circle of fifths, on any track, saved with the session. It passes audio straight through, so leave it on.
Get Cafecito, free →Quick answers
What note is 440 Hz?
440 Hz is A4, the A above middle C. It is the standard tuning reference (ISO 16) that most instruments and tuners use.
What frequency is middle C?
Middle C (C4, MIDI note 60) is 261.63 Hz when A4 is 440 Hz.
How do I convert a frequency to a note?
Work out 69 + 12 × log₂(frequency ÷ 440) and round it to get the MIDI note number. Whatever was left over before rounding, times 100, is how many cents sharp or flat the frequency is. The converter above does it as you type.
What note is 432 Hz?
432 Hz is A4 tuned down by 31.8 cents. It is not a different note, just a lower reference pitch.
What is the frequency of the low E string on a guitar?
In standard tuning the low E (E2) is 82.41 Hz and the high E (E4) is 329.63 Hz.
What note is 60 Hz hum?
60 Hz sits 49 cents below B1, between B♭1 and B1. 50 Hz hum is 35 cents above G1.
More free music tools
Online guitar tuner
Tune guitar, bass or ukulele with your mic. Finds the string for you, in standard or drop tunings.
Song key and BPM finder
Drop in a song to get its key, Camelot code and tempo, with harmonic mixing matches.
LUFS meter
Integrated loudness, true peak and loudness range, and what Spotify, Apple Music and YouTube will do to your master.
Chord finder
Click notes on a piano to name any chord or slash chord, or build a chord and hear it.
Online tone generator
Any frequency, sweeps, and white, pink and brown noise. Test speakers, subs and left and right.