CONVERT Function

CONVERT.js

// Copyright (c) 2012 Sutoiku, Inc. (MIT License)

function CONVERT(number, from_unit, to_unit) {
  // Return error if number is a non-numeric value
  if (isNaN(number)) return '#VALUE!';

  // List of units supported by CONVERT and units defined by the International System of Units
  // [Name, Symbol, Alternate symbols, Quantity, International System of Units, Supported by CONVERT, Conversion ratio]
  var units = [
    ["a.u. of action","ħ",null,"action",false,false,1.05457168181818e-34],
    ["a.u. of charge","e",null,"electric_charge",false,false,1.60217653141414e-19],
    ["a.u. of energy","Eh",null,"energy",false,false,4.35974417757576e-18],
    ["a.u. of length","a₀",null,"length",false,false,5.29177210818182e-11],
    ["a.u. of mass","mₑ",null,"mass",false,false,9.10938261616162e-31],
    ["a.u. of time","ħ/Eh",null,"time",false,false,2.41888432650516e-17],
    ["admiralty knot","admkn",null,"speed",false,true,0.514773333],
    ["ampere","A",null,"electric_current",true,false,1],
    ["ampere per meter","A/m",null,"magnetic_field_intensity",true,false,1],
    ["ångström","Å",["ang"],"length",false,true,1e-10],
    ["are","ar",null,"area",false,true,100],
    ["astronomical unit","ua",null,"length",false,false,1.49597870691667e-11],
    ["bar","bar",null,"pressure",false,false,100000],
    ["barn","b",null,"area",false,false,1e-28],
    ["becquerel","Bq",null,"radioactivity",true,false,1],
    ["bit","bit",["b"],"information",false,true,1],
    ["btu","BTU",["btu"],"energy",false,true,1055.05585262],
    ["byte","byte",null,"information",false,true,8],
    ["candela","cd",null,"luminous_intensity",true,false,1],
    ["candela per square metre","cd/m²",null,"luminance",true,false,1],
    ["coulomb","C",null,"electric_charge",true,false,1],
    ["cubic ångström","ang3",["ang^3"],"volume",false,true,1e-30],
    ["cubic foot","ft3",["ft^3"],"volume",false,true,0.028316846592],
    ["cubic inch","in3",["in^3"],"volume",false,true,0.000016387064],
    ["cubic light-year","ly3",["ly^3"],"volume",false,true,8.46786664623715e-47],
    ["cubic metre","m³",null,"volume",true,true,1],
    ["cubic mile","mi3",["mi^3"],"volume",false,true,4168181825.44058],
    ["cubic nautical mile","Nmi3",["Nmi^3"],"volume",false,true,6352182208],
    ["cubic Pica","Pica3",["Picapt3","Pica^3","Picapt^3"],"volume",false,true,7.58660370370369e-8],
    ["cubic yard","yd3",["yd^3"],"volume",false,true,0.764554857984],
    ["cup","cup",null,"volume",false,true,0.0002365882365],
    ["dalton","Da",["u"],"mass",false,false,1.66053886282828e-27],
    ["day","d",["day"],"time",false,true,86400],
    ["degree","°",null,"angle",false,false,0.0174532925199433],
    ["degrees Rankine","Rank",null,"temperature",false,true,0.555555555555556],
    ["dyne","dyn",["dy"],"force",false,true,0.00001],
    ["electronvolt","eV",["ev"],"energy",false,true,1.60217656514141],
    ["ell","ell",null,"length",false,true,1.143],
    ["erg","erg",["e"],"energy",false,true,1e-7],
    ["farad","F",null,"electric_capacitance",true,false,1],
    ["fluid ounce","oz",null,"volume",false,true,0.0000295735295625],
    ["foot","ft",null,"length",false,true,0.3048],
    ["foot-pound","flb",null,"energy",false,true,1.3558179483314],
    ["gal","Gal",null,"acceleration",false,false,0.01],
    ["gallon","gal",null,"volume",false,true,0.003785411784],
    ["gauss","G",["ga"],"magnetic_flux_density",false,true,1],
    ["grain","grain",null,"mass",false,true,0.0000647989],
    ["gray","Gy",null,"absorbed_dose",true,false,1],
    ["gross registered ton","GRT",["regton"],"volume",false,true,2.8316846592],
    ["hectare","ha",null,"area",false,true,10000],
    ["henry","H",null,"inductance",true,false,1],
    ["hertz","Hz",null,"frequency",true,false,1],
    ["horsepower","HP",["h"],"power",false,true,745.69987158227],
    ["horsepower-hour","HPh",["hh","hph"],"energy",false,true,2684519.538],
    ["hour","h",["hr"],"time",false,true,3600],
    ["imperial gallon (U.K.)","uk_gal",null,"volume",false,true,0.00454609],
    ["imperial hundredweight","lcwt",["uk_cwt","hweight"],"mass",false,true,50.802345],
    ["imperial quart (U.K)","uk_qt",null,"volume",false,true,0.0011365225],
    ["imperial ton","brton",["uk_ton","LTON"],"mass",false,true,1016.046909],
    ["inch","in",null,"length",false,true,0.0254],
    ["international acre","uk_acre",null,"area",false,true,4046.8564224],
    ["IT calorie","cal",null,"energy",false,true,4.1868],
    ["joule","J",null,"energy",true,true,1],
    ["katal","kat",null,"catalytic_activity",true,false,1],
    ["kelvin","K",["kel"],"temperature",true,true,1],
    ["kilogram","kg",null,"mass",true,true,1],
    ["knot","kn",null,"speed",false,true,0.514444444444444],
    ["light-year","ly",null,"length",false,true,9460730472580800],
    ["litre","L",["l","lt"],"volume",false,true,0.001],
    ["lumen","lm",null,"luminous_flux",true,false,1],
    ["lux","lx",null,"illuminance",true,false,1],
    ["maxwell","Mx",null,"magnetic_flux",false,false,1e-18],
    ["measurement ton","MTON",null,"volume",false,true,1.13267386368],
    ["meter per hour","m/h",["m/hr"],"speed",false,true,0.00027777777777778],
    ["meter per second","m/s",["m/sec"],"speed",true,true,1],
    ["meter per second squared","m⋅s⁻²",null,"acceleration",true,false,1],
    ["parsec","pc",["parsec"],"length",false,true,30856775814671900],
    ["meter squared per second","m²/s",null,"kinematic_viscosity",true,false,1],
    ["metre","m",null,"length",true,true,1],
    ["miles per hour","mph",null,"speed",false,true,0.44704],
    ["millimetre of mercury","mmHg",null,"pressure",false,false,133.322],
    ["minute","′",null,"angle",false,false,0.000290888208665722],
    ["minute","min",["mn"],"time",false,true,60],
    ["modern teaspoon","tspm",null,"volume",false,true,0.000005],
    ["mole","mol",null,"amount_of_substance",true,false,1],
    ["morgen","Morgen",null,"area",false,true,2500],
    ["n.u. of action","ħ",null,"action",false,false,1.05457168181818e-34],
    ["n.u. of mass","mₑ",null,"mass",false,false,9.10938261616162e-31],
    ["n.u. of speed","c₀",null,"speed",false,false,299792458],
    ["n.u. of time","ħ/(me⋅c₀²)",null,"time",false,false,1.28808866778687e-21],
    ["nautical mile","M",["Nmi"],"length",false,true,1852],
    ["newton","N",null,"force",true,true,1],
    ["œrsted","Oe ",null,"magnetic_field_intensity",false,false,79.5774715459477],
    ["ohm","Ω",null,"electric_resistance",true,false,1],
    ["ounce mass","ozm",null,"mass",false,true,0.028349523125],
    ["pascal","Pa",null,"pressure",true,false,1],
    ["pascal second","Pa⋅s",null,"dynamic_viscosity",true,false,1],
    ["pferdestärke","PS",null,"power",false,true,735.49875],
    ["phot","ph",null,"illuminance",false,false,0.0001],
    ["pica (1/6 inch)","pica",null,"length",false,true,0.00035277777777778],
    ["pica (1/72 inch)","Pica",["Picapt"],"length",false,true,0.00423333333333333],
    ["poise","P",null,"dynamic_viscosity",false,false,0.1],
    ["pond","pond",null,"force",false,true,0.00980665],
    ["pound force","lbf",null,"force",false,true,4.4482216152605],
    ["pound mass","lbm",null,"mass",false,true,0.45359237],
    ["quart","qt",null,"volume",false,true,0.000946352946],
    ["radian","rad",null,"angle",true,false,1],
    ["second","″",null,"angle",false,false,0.00000484813681109536],
    ["second","s",["sec"],"time",true,true,1],
    ["short hundredweight","cwt",["shweight"],"mass",false,true,45.359237],
    ["siemens","S",null,"electrical_conductance",true,false,1],
    ["sievert","Sv",null,"equivalent_dose",true,false,1],
    ["slug","sg",null,"mass",false,true,14.59390294],
    ["square ångström","ang2",["ang^2"],"area",false,true,1e-20],
    ["square foot","ft2",["ft^2"],"area",false,true,0.09290304],
    ["square inch","in2",["in^2"],"area",false,true,0.00064516],
    ["square light-year","ly2",["ly^2"],"area",false,true,8.95054210748189e+31],
    ["square meter","m²",null,"area",true,true,1],
    ["square mile","mi2",["mi^2"],"area",false,true,2589988.110336],
    ["square nautical mile","Nmi2",["Nmi^2"],"area",false,true,3429904],
    ["square Pica","Pica2",["Picapt2","Pica^2","Picapt^2"],"area",false,true,0.00001792111111111],
    ["square yard","yd2",["yd^2"],"area",false,true,0.83612736],
    ["statute mile","mi",null,"length",false,true,1609.344],
    ["steradian","sr",null,"solid_angle",true,false,1],
    ["stilb","sb",null,"luminance",false,false,0.0001],
    ["stokes","St",null,"kinematic_viscosity",false,false,0.0001],
    ["stone","stone",null,"mass",false,true,6.35029318],
    ["tablespoon","tbs",null,"volume",false,true,0.0000147868],
    ["teaspoon","tsp",null,"volume",false,true,0.00000492892],
    ["tesla","T",null,"magnetic_flux_density",true,true,1],
    ["thermodynamic calorie","c",null,"energy",false,true,4.184],
    ["ton","ton",null,"mass",false,true,907.18474],
    ["tonne","t",null,"mass",false,false,1000],
    ["U.K. pint","uk_pt",null,"volume",false,true,0.00056826125],
    ["U.S. bushel","bushel",null,"volume",false,true,0.03523907],
    ["U.S. oil barrel","barrel",null,"volume",false,true,0.158987295],
    ["U.S. pint","pt",["us_pt"],"volume",false,true,0.000473176473],
    ["U.S. survey mile","survey_mi",null,"length",false,true,1609.347219],
    ["U.S. survey/statute acre","us_acre",null,"area",false,true,4046.87261],
    ["volt","V",null,"voltage",true,false,1],
    ["watt","W",null,"power",true,true,1],
    ["watt-hour","Wh",["wh"],"energy",false,true,3600],
    ["weber","Wb",null,"magnetic_flux",true,false,1],
    ["yard","yd",null,"length",false,true,0.9144],
    ["year","yr",null,"time",false,true,31557600]];

  // Binary prefixes
  // [Name, Prefix power of 2 value, Previx value, Abbreviation, Derived from]
  var binary_prefixes = {
    Yi: ["yobi",80,1208925819614629174706176,"Yi","yotta"],
    Zi: ["zebi",70,1180591620717411303424,"Zi","zetta"],
    Ei: ["exbi",60,1152921504606846976,"Ei","exa"],
    Pi: ["pebi",50,1125899906842624,"Pi","peta"],
    Ti: ["tebi",40,1099511627776,"Ti","tera"],
    Gi: ["gibi",30,1073741824,"Gi","giga"],
    Mi: ["mebi",20,1048576,"Mi","mega"],
    ki: ["kibi",10,1024,"ki","kilo"]
  };

  // Unit prefixes
  // [Name, Multiplier, Abbreviation]
  var unit_prefixes = {
    Y: ["yotta",1e+24,"Y"],
    Z: ["zetta",1e+21,"Z"],
    E: ["exa",1e+18,"E"],
    P: ["peta",1e+15,"P"],
    T: ["tera",1e+12,"T"],
    G: ["giga",1e+09,"G"],
    M: ["mega",1e+06,"M"],
    k: ["kilo",1e+03,"k"],
    h: ["hecto",1e+02,"h"],
    e: ["dekao",1e+01,"e"],
    d: ["deci",1e-01,"d"],
    c: ["centi",1e-02,"c"],
    m: ["milli",1e-03,"m"],
    u: ["micro",1e-06,"u"],
    n: ["nano",1e-09,"n"],
    p: ["pico",1e-12,"p"],
    f: ["femto",1e-15,"f"],
    a: ["atto",1e-18,"a"],
    z: ["zepto",1e-21,"z"],
    y: ["yocto",1e-24,"y"]
  };
    
  // Initialize units and multipliers
  var from = null;
  var to = null;
  var base_from_unit = from_unit;
  var base_to_unit = to_unit;
  var from_multiplier = 1;
  var to_multiplier = 1;

  // Lookup from and to units
  for (var i = 0; i < units.length; i++) {
    var alt = (units[i][2] === null) ? [] : units[i][2];
    if (units[i][1] === base_from_unit || alt.indexOf(base_from_unit) >= 0) {
      from = units[i];
    }
    if (units[i][1] === base_to_unit || alt.indexOf(base_to_unit) >= 0) {
      to = units[i];
    }
  }
  
  // Lookup from prefix
  if (from === null) {
    var from_binary_prefix = binary_prefixes[from_unit.substring(0, 2)];
    var from_unit_prefix = unit_prefixes[from_unit.substring(0, 1)];

    // Handle dekao unit prefix (only unit prefix with two characters)
    if (from_unit.substring(0, 2) === 'da') {
      from_unit_prefix = ["dekao",1e+01,"da"];
    }

    // Handle binary prefixes first (so that 'Yi' is processed before 'Y')
    if (from_binary_prefix) {
      from_multiplier = from_binary_prefix[2];
      base_from_unit = from_unit.substring(2);
    } else if (from_unit_prefix) {
      from_multiplier = from_unit_prefix[1];
      base_from_unit = from_unit.substring(from_unit_prefix[2].length);    
    }

    // Lookup from unit
    for (var j = 0; j < units.length; j++) {
      var alt = (units[j][2] === null) ? [] : units[j][2];
      if (units[j][1] === base_from_unit || alt.indexOf(base_from_unit) >= 0) {
        from = units[j];
      }
    }
  }

  // Lookup to prefix
  if (to === null) {
    var to_binary_prefix = binary_prefixes[to_unit.substring(0, 2)];
    var to_unit_prefix = unit_prefixes[to_unit.substring(0, 1)];

    // Handle dekao unit prefix (only unit prefix with two characters)
    if (to_unit.substring(0, 2) === 'da') {
      to_unit_prefix = ["dekao",1e+01,"da"];
    }

    // Handle binary prefixes first (so that 'Yi' is processed before 'Y')
    if (to_binary_prefix) {
      to_multiplier = to_binary_prefix[2];
      base_to_unit = to_unit.substring(2);
    } else if (to_unit_prefix) {
      to_multiplier = to_unit_prefix[1];
      base_to_unit = to_unit.substring(to_unit_prefix[2].length);    
    }

    // Lookup to unit
    for (var k = 0; k < units.length; k++) {
      var alt = (units[k][2] === null) ? [] : units[k][2];
      if (units[k][1] === base_to_unit || alt.indexOf(base_to_unit) >= 0) {
        to = units[k];
      }
    }
  }
  
  // Return error if a unit does not exist
  if (from === null || to === null) return '#N/A';
  
  // Return error if units represent different quantities
  if (from[3] !== to[3]) return '#N/A';
  
  // Return converted number
  return number * from[6] * from_multiplier / (to[6] * to_multiplier);
}