Note to Frequency Chart
A chart of musical note names to frequencies in hertz across every octave, using equal temperament with A4 at 440 Hz, plus a note to frequency converter.
| 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 | 130.81 | 261.63 | 523.25 | 1046.50 | 2093.00 | 4186.01 |
| C# | 17.32 | 34.65 | 69.30 | 138.59 | 277.18 | 554.37 | 1108.73 | 2217.46 | 4434.92 |
| D | 18.35 | 36.71 | 73.42 | 146.83 | 293.66 | 587.33 | 1174.66 | 2349.32 | 4698.64 |
| D# | 19.45 | 38.89 | 77.78 | 155.56 | 311.13 | 622.25 | 1244.51 | 2489.02 | 4978.03 |
| E | 20.60 | 41.20 | 82.41 | 164.81 | 329.63 | 659.26 | 1318.51 | 2637.02 | 5274.04 |
| F | 21.83 | 43.65 | 87.31 | 174.61 | 349.23 | 698.46 | 1396.91 | 2793.83 | 5587.65 |
| F# | 23.12 | 46.25 | 92.50 | 185.00 | 369.99 | 739.99 | 1479.98 | 2959.96 | 5919.91 |
| G | 24.50 | 49.00 | 98.00 | 196.00 | 392.00 | 783.99 | 1567.98 | 3135.96 | 6271.93 |
| G# | 25.96 | 51.91 | 103.83 | 207.65 | 415.30 | 830.61 | 1661.22 | 3322.44 | 6644.88 |
| A | 27.50 | 55.00 | 110.00 | 220.00 | 440.00 | 880.00 | 1760.00 | 3520.00 | 7040.00 |
| A# | 29.14 | 58.27 | 116.54 | 233.08 | 466.16 | 932.33 | 1864.66 | 3729.31 | 7458.62 |
| B | 30.87 | 61.74 | 123.47 | 246.94 | 493.88 | 987.77 | 1975.53 | 3951.07 | 7902.13 |
Values use twelve tone equal temperament with A4 fixed at 440 Hz. Sharps share a pitch with the enharmonic flat, so C# equals Db.
This note frequency chart lists the pitch of every musical note in hertz, from the low rumble of C0 up to the highest piano notes, using equal temperament with A4 fixed at 440 Hz. Use it to check the frequency of a note when programming a synth, tuning by ear with the tone generator, or understanding what your tuner is telling you. A small converter lets you look up a single note or find the nearest note to a frequency.
How note frequencies are calculated
In twelve tone equal temperament, every semitone is the same ratio apart: the twelfth root of two, which is about 1.059463. Starting from the reference of A4 at 440 Hz, you multiply by that ratio to go up a semitone and divide by it to go down. Because there are twelve semitones in an octave, going up twelve steps doubles the frequency exactly, so A5 is 880 Hz and A3 is 220 Hz. This simple rule generates the frequency of every note on the chart, and it is why the numbers grow slowly in the bass and quickly in the treble.
The chart uses scientific pitch notation, where the number after the note name is the octave and middle C is written C4. Sharps and flats share a pitch in equal temperament, so C sharp and D flat are the same frequency. Standard concert pitch pins A4 to 440 Hz, though some ensembles tune slightly higher, for example to 442 or 443 Hz, which shifts every value on the chart by the same proportion.
Using the chart and converter
Scan down the table to find a note and read its frequency, or use it in reverse to see which note a frequency lands on. The built in converter accepts a note name and octave and returns the exact frequency, and it also takes a frequency in hertz and returns the closest note along with how many cents away it is. That pairs naturally with the chromatic tuner, which reports the same note and cents from a live microphone signal, and with the tone generator, which can play any of these frequencies back to you as a reference pitch.
Frequently asked questions
What frequency is A4?
A4 is 440 Hz, the international standard for concert pitch. Every other note on the chart is derived from this reference using equal temperament, so A5 is 880 Hz and A3 is 220 Hz.
What is middle C and its frequency?
Middle C is C4 in scientific pitch notation and sits at about 261.63 Hz when A4 is 440 Hz. It is the C nearest the middle of a piano keyboard.
Why are sharps and flats the same frequency?
In twelve tone equal temperament, enharmonic notes such as C sharp and D flat are tuned to the identical pitch. They are written differently for musical reasons but sound the same, so they share one frequency on the chart.
Can I use a different reference than 440 Hz?
The chart is built on the standard A4 equals 440 Hz. If your ensemble tunes to 442 or 443 Hz, every frequency shifts up by the same proportion, so multiply each value by your reference divided by 440.