Note Frequency Calculator
Type a note name to get its frequency in Hz and MIDI number, or type a frequency to get the nearest note and how many cents sharp or flat it is. The chart below the tool lists every note from octave 0 to 8.
Letter, optional # or b, octave: C4, F#3, Bb2
Any pitch, e.g. a tuner reading or a sample's root
440 standard; 442 orchestral; 432 alternative
A4 is
440.00 Hz
MIDI note 69 · 440 × 2^((69 − 69) ÷ 12)
432 Hz is nearest
A4
-31.8 cents from 440.00 Hz · MIDI 69
Note frequency chart, A4 = 440 Hz
| Note | Oct 0 | Oct 1 | Oct 2 | Oct 3 | Oct 4 | Oct 5 | Oct 6 | Oct 7 | Oct 8 |
|---|---|---|---|---|---|---|---|---|---|
| C | 16.35 | 32.70 | 65.41 | 130.8 | 261.6 | 523.3 | 1047 | 2093 | 4186 |
| C# | 17.32 | 34.65 | 69.30 | 138.6 | 277.2 | 554.4 | 1109 | 2217 | 4435 |
| D | 18.35 | 36.71 | 73.42 | 146.8 | 293.7 | 587.3 | 1175 | 2349 | 4699 |
| D# | 19.45 | 38.89 | 77.78 | 155.6 | 311.1 | 622.3 | 1245 | 2489 | 4978 |
| E | 20.60 | 41.20 | 82.41 | 164.8 | 329.6 | 659.3 | 1319 | 2637 | 5274 |
| F | 21.83 | 43.65 | 87.31 | 174.6 | 349.2 | 698.5 | 1397 | 2794 | 5588 |
| F# | 23.12 | 46.25 | 92.50 | 185.0 | 370.0 | 740.0 | 1480 | 2960 | 5920 |
| G | 24.50 | 49.00 | 98.00 | 196.0 | 392.0 | 784.0 | 1568 | 3136 | 6272 |
| G# | 25.96 | 51.91 | 103.8 | 207.7 | 415.3 | 830.6 | 1661 | 3322 | 6645 |
| A | 27.50 | 55.00 | 110.0 | 220.0 | 440.0 | 880.0 | 1760 | 3520 | 7040 |
| A# | 29.14 | 58.27 | 116.5 | 233.1 | 466.2 | 932.3 | 1865 | 3729 | 7459 |
| B | 30.87 | 61.74 | 123.5 | 246.9 | 493.9 | 987.8 | 1976 | 3951 | 7902 |
Frequencies in Hz. Octave numbers follow scientific pitch notation (middle C = C4 = MIDI 60). Each octave doubles; each semitone multiplies by 2^(1⁄12) ≈ 1.05946.
Equal temperament in one line
Twelve-tone equal temperament splits the octave into twelve equal ratios, so each semitone multiplies the frequency by 2^(1⁄12) ≈ 1.059463. Pin one note (A4 = 440 Hz) and every other note follows. This is why the chart doubles down each row when you move a column to the right: an octave is twelve semitones, and 1.059463^12 = 2. Cents divide each semitone into 100 equal steps; most people hear a difference of about 5 to 10 cents on a sustained tone, which is why tuners show them.
Landmark notes
| Note | Hz | MIDI | Why it matters |
|---|---|---|---|
| E1 | 41.20 | 28 | Lowest note on a 4-string bass guitar, and on a piano B0 is the bottom key at 30.9 Hz |
| E2 | 82.41 | 40 | Low E on a guitar in standard tuning |
| A2 | 110.00 | 45 | Open A string on guitar; typical male vocal low range |
| C4 | 261.63 | 60 | Middle C; MIDI 60 |
| A4 | 440.00 | 69 | Concert pitch, the tuning reference |
| C5 | 523.25 | 72 | Soprano comfortable range starts here |
| D6 | 1174.66 | 86 | Fret 22 on the high E string, the top of a 22-fret guitar; E6 is fret 24 on a 24-fret neck |
| C8 | 4186.01 | 108 | Top key on an 88-key piano |
Using frequencies in a mix
Knowing a song's key tells you where the bass fundamentals sit: a track in F has its root at 43.7 Hz (F1) or 87.3 Hz (F2), so a kick tuned to F or C will sit with the bass instead of fighting it. Resonant EQ cuts land better on a note than on a round number, and a sampler's root-note field is just this conversion the other way. The 432 Hz box exists so you can re-tune the whole chart to match a reference recording or an instrument that is not at concert pitch.
Frequently Asked Questions
How do I calculate the frequency of a note?
Count semitones from A4 (440 Hz) and use f = 440 × 2^(n ÷ 12). C5 is three semitones above A4: 440 × 2^(3⁄12) = 523.25 Hz. A3 is twelve below, so it halves to 220 Hz. With MIDI numbers the same formula is f = 440 × 2^((midi − 69) ÷ 12), since A4 is MIDI 69.
How do I turn a frequency into a note?
Reverse the formula: semitones from A4 = 12 × log2(f ÷ 440). Round to the nearest whole semitone for the note name, and the remainder × 100 is the offset in cents. 432 Hz gives −0.32 semitones, so it is A4 flat by 32 cents. A tuner does exactly this in real time.
What is middle C in Hz, and which octave is it?
Middle C is C4, 261.63 Hz at A4 = 440, MIDI note 60. Octave numbers change at C, so B3 is just below C4. Some software (older Yamaha gear, some DAWs) labels middle C as C3; the frequency is the same, only the label moves.
What is the difference between 440 Hz and 432 Hz tuning?
A4 = 440 Hz has been the ISO standard since 1955 and is what nearly all recorded music, samples and instruments use. 432 Hz is 32 cents flat of that; some people prefer its sound, but the claims about it are not supported by evidence. Orchestras sometimes tune to 441 or 442 Hz for brightness. Change the reference box above and the whole chart re-tunes.
What frequency ranges matter for mixing?
Sub bass 20 to 60 Hz (E1 is 41 Hz, the lowest note on a four-string bass); bass 60 to 250 Hz (kick fundamentals live around 50 to 80 Hz, an A2 is 110 Hz); low mids 250 to 500 Hz; mids 500 Hz to 2 kHz, where most vocal fundamentals sit (C4 to C6 is 262 to 1,047 Hz); presence 2 to 5 kHz; air above 10 kHz, which is above the highest fundamental on a piano (C8, 4,186 Hz).
These tools use the standard tempo, pitch and timing formulas (60,000 ÷ BPM, A4 = 440 Hz equal temperament, 1,200 cents per octave). They run in your browser; the tap counter uses your keyboard or mouse timing, so expect a beat or two of settling before the reading is stable.