note frequency value

notevalues.json

var noteValues = {
    'C0': 16.35,
    'C#0': 17.32,
    'Db0': 17.32,
    'D0': 18.35,
    'D#0': 19.45,
    'Eb0': 19.45,
    'E0': 20.60,
    'F0': 21.83,
    'F#0': 23.12,
    'Gb0': 23.12,
    'G0': 24.50,
    'G#0': 25.96,
    'Ab0': 25.96,
    'A0': 27.50,
    'A#0': 29.14,
    'Bb0': 29.14,
    'B0': 30.87,
    'C1': 32.70,
    'C#1': 34.65,
    'Db1': 34.65,
    'D1': 36.71,
    'D#1': 38.89,
    'Eb1': 38.89,
    'E1': 41.20,
    'F1': 43.65,
    'F#1': 46.25,
    'Gb1': 46.25,
    'G1': 49.00,
    'G#1': 51.91,
    'Ab1': 51.91,
    'A1': 55.00,
    'A#1': 58.27,
    'Bb1': 58.27,
    'B1': 61.74,
    'C2': 65.41,
    'C#2': 69.30,
    'Db2': 69.30,
    'D2': 73.42,
    'D#2': 77.78,
    'Eb2': 77.78,
    'E2': 82.41,
    'F2': 87.31,
    'F#2': 92.50,
    'Gb2': 92.50,
    'G2': 98.00,
    'G#2': 103.83,
    'Ab2': 103.83,
    'A2': 110.00,
    'A#2': 116.54,
    'Bb2': 116.54,
    'B2': 123.47,
    'C3': 130.81,
    'C#3': 138.59,
    'Db3': 138.59,
    'D3': 146.83,
    'D#3': 155.56,
    'Eb3': 155.56,
    'E3': 164.81,
    'F3': 174.61,
    'F#3': 185.00,
    'Gb3': 185.00,
    'G3': 196.00,
    'G#3': 207.65,
    'Ab3': 207.65,
    'A3': 220.00,
    'A#3': 233.08,
    'Bb3': 233.08,
    'B3': 246.94,
    'C4': 261.63,
    'C#4': 277.18,
    'Db4': 277.18,
    'D4': 293.66,
    'D#4': 311.13,
    'Eb4': 311.13,
    'E4': 329.63,
    'F4': 349.23,
    'F#4': 369.99,
    'Gb4': 369.99,
    'G4': 392.00,
    'G#4': 415.30,
    'Ab4': 415.30,
    'A4': 440.00,
    'A#4': 466.16,
    'Bb4': 466.16,
    'B4': 493.88,
    'C5': 523.25,
    'C#5': 554.37,
    'Db5': 554.37,
    'D5': 587.33,
    'D#5': 622.25,
    'Eb5': 622.25,
    'E5': 659.26,
    'F5': 698.46,
    'F#5': 739.99,
    'Gb5': 739.99,
    'G5': 783.99,
    'G#5': 830.61,
    'Ab5': 830.61,
    'A5': 880.00,
    'A#5': 932.33,
    'Bb5': 932.33,
    'B5': 987.77,
    'C6': 1046.50,
    'C#6': 1108.73,
    'Db6': 1108.73,
    'D6': 1174.66,
    'D#6': 1244.51,
    'Eb6': 1244.51,
    'E6': 1318.51,
    'F6': 1396.91,
    'F#6': 1479.98,
    'Gb6': 1479.98,
    'G6': 1567.98,
    'G#6': 1661.22,
    'Ab6': 1661.22,
    'A6': 1760.00,
    'A#6': 1864.66,
    'Bb6': 1864.66,
    'B6': 1975.53,
    'C7': 2093.00,
    'C#7': 2217.46,
    'Db7': 2217.46,
    'D7': 2349.32,
    'D#7': 2489.02,
    'Eb7': 2489.02,
    'E7': 2637.02,
    'F7': 2793.83,
    'F#7': 2959.96,
    'Gb7': 2959.96,
    'G7': 3135.96,
    'G#7': 3322.44,
    'Ab7': 3322.44,
    'A7': 3520.00,
    'A#7': 3729.31,
    'Bb7': 3729.31,
    'B7': 3951.07,
    'C8': 4186.01
}

Ur the man! Using this for a hackathon now!

why does it stop at c8?

Thanks!
Source possibly comes from https://pages.mtu.edu/~suits/notefreqs.html.

@aluminumChassis because its just using a formula anyway, to get c9 just do c8 * 2 same for any other note, ie: for A10 multiply A9 by 2

Thanks for this info !

var NOTES = ["C", "C#", "D", "Eb", "E", "F", "F#", "G", "G#", "A", "Bb", "B"];
function getPitch(note, octave) {
    // ("A", 4) => 440
    // multiply by 2^(1/12) N times to get N steps higher
    var step = NOTES.indexOf(note);
    var power = Math.pow(2, (octave * 12 + step - 57)/12);
    var pitch = 440 * power;
    return pitch;
}

Found this too late 🤣 , love @bblack 's function to get the frequencies dynamically, but as I already did the work, here's an object notation of the same, might come handy to someone:

const map = {
    'C': [16.35, 32.70, 65.41, 130.8, 261.6, 523.3, 1047, 2093, 4186],
    'C#': [17.32, 34.65, 69.3, 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],
    'Eb': [19.45, 38.89, 77.78, 155.6, 311.1, 622.3, 1245, 2489, 4978],
    'E': [20.6, 41.2, 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, 92.5, 185, 370, 740, 1480, 2960, 5920],
    'G': [24.5, 49, 98, 196, 392, 784, 1568, 3136, 6272],
    'G#': [25.96, 51.91, 103.8, 207.7, 415.3, 830.6, 1661, 3322, 6645],
    'A': [27.5, 55, 110, 220, 440, 880, 1760, 3520, 7040],
    'Bb': [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],
};

Thank you all, these are great!