How can I format big numbers with toLocaleString?

Question

I need to format really big numbers to billions or millions like this:

$ 100.00 B or $90.00 M

// this is my code so far:

var currency = doc.stock.exchange.currency; //this is how I get the currency
  var formatNumberNat = val.toLocaleString(
    'en-US', {
      style: 'currency',
      currency: currency
    }
  );
return formatNumberNat; /* €90,102,409,320.00 */

the problem with numeral is that it does not get currencies, only language :( — Lido Fernandez, Jun 13 '16 at 22:19

score 1 · Answer 1 · answered Mar 21 '19 at 16:44

You can use a function like this one to wrap toLocaleString:

const currencyToString = (
  num, {
    locale = "en-US",
    currency = "USD",
    minimumFractionDigits = 2,
    maximumFractionDigits,
    abbreviationFormats
  }
) => {
  if (num == null || typeof num !== "number") {
    // null, undefined, non-numeric, return what was provided
    return num;
  }

  let format;
  if (abbreviationFormats != null) {
    // formats were provided, find one that works
    format = abbreviationFormats.find(f => num >= f.value);
  }

  if (format != null) {
    // apply the format, insert the symbol next to the numeric portion of the formatted string
    const {
      value,
      symbol
    } = format;
    const formatted = (num / value).toLocaleString(locale, {
      style: "currency",
      currency,
      minimumFractionDigits,
      maximumFractionDigits
    });
    const parts = formatted.match(/([\D]*)([\d.,]+)([\D]*)/)
    return `${parts[1]}${parts[2]}${symbol}${parts[3]}`
  }

  // otherwise, use the number as provided
  return num.toLocaleString(locale, {
    style: "currency",
    currency,
    minimumFractionDigits,
    maximumFractionDigits
  });
};

This will accept an optional structure of formats that can be used to abbreviate large numbers:

const formats = [
  { value: 1e12, symbol: "T" },
  { value: 1e9, symbol: "B" },
  { value: 1e6, symbol: "M" },
  { value: 1e3, symbol: "K" }  
];

Here is a codesandbox with a lot of tests with a few combinations of locale and currency.

score 0 · Answer 2 · edited May 23 '17 at 12:01

0

function nFormatter(num, digits) {
  var si = [
    { value: 1E18, symbol: "E" },
    { value: 1E15, symbol: "P" },
    { value: 1E12, symbol: "T" },
    { value: 1E9,  symbol: "G" },
    { value: 1E6,  symbol: "M" },
    { value: 1E3,  symbol: "k" }
  ], i;
  for (i = 0; i < si.length; i++) {
    if (num >= si[i].value) {
      return (num / si[i].value).toFixed(digits).replace(/\.0+$|(\.[0-9]*[1-9])0+$/, "$1") + si[i].symbol;
    }
  }
  return num.toString();
}
console.log(nFormatter(123, 1));       // 123
console.log(nFormatter(1234, 1));      // 1.2k
console.log(nFormatter(100000000, 1)); // 100M
console.log(nFormatter(299792458, 1)); // 299.8M
console.log(nFormatter(759878, 1));    // 759.9k
console.log(nFormatter(759878, 0));    // 760k

How to format a number as 2.5K if a thousand or more, otherwise 900 in javascript?

edited May 23 '17 at 12:01

Community

1
1

answered Jun 13 '16 at 22:21

WickedFan

356
2
12

The request was how to do this using `toLocaleString`, this assumes the currency symbol is `$`. – Ken Gregory Mar 21 '19 at 15:39
toLocaleString would then also need to be put through a currency exchange library. toLocaleString only changes characters ie: Arabic number to Chinese number as well as the currency symbol. As you see in his question, the code stipulates toLocalString('en-US'(style option) which means $ will be replaced by whatever sign he wants the currency in. The 'Replace portion of '$'' can then be omitted. – WickedFan Mar 22 '19 at 21:18
Since a locale of `en-US` doesn't imply a currency symbol of `$` and currency is specified by a parameter and it is expected that the default behavior of `toLocaleString` is applied (`minimumFractionDigits` is defaulted based on the value specified for `currency`, etc.), this answer is insufficent for the question. – Ken Gregory Mar 25 '19 at 14:41

score -1 · Answer 3 · answered Jun 13 '16 at 22:21

-1

You can use a function like this:

function formatB(n) {
    if (n > 999999999) 
        return "$" + (n/1000000000).toFixed(2) + "B";
    else if(n > 999999)
        return "$" + (n/1000000).toFixed(2) + "M";
    else
        return n;
}

answered Jun 13 '16 at 22:21

Nicolas Rojas

127
4

This assumes a currency of `USD` and a locale of `en-US`. The original question was about using `toLocaleString`. – Ken Gregory Mar 21 '19 at 17:55

How can I format big numbers with toLocaleString?

3 Answers3