Formatting Compact Numbers with JavaScript

Whether you’re using any social media apps or YouTube, you might have seen that the number of likes, subscribers/followers, comments, etc., are always shown in rounded, compact form, like 23K instead of 23145. This article will look at the JavaScript Internationalization API and how to produce compact numbers with it.

Compact numbers are the compact/concise way of representing large numbers. Like using "K" for thousands, "M" for millions, "B" for billions, etc.

The JavaScript Internationalization API is a built-in library that is reliable and flexible for formatting compact numbers and is consistent across different browsers. The JS Internationalization API is a more efficient approach than using third-party packages.

How to use Intl.NumberFormat Object?

An Intl.NumberFormat object is part of the JS Internationalization API and is used to format numbers according to a particular locale and options.

When developers use the Intl.NumberFormat objects, their applications display numbers consistently regardless of the user's locale or preference.

As a first step, you must create an instance of the Intl.NumberFormat object by calling its constructor with the new keyword.

let formater = new Intl.NumberFormat();
let formater = new Intl.NumberFormat(locales);
let formater = new Intl.NumberFormat(locales, options);

• Locales: It specifies the language and the region to format the number like en-US (US English), fr-FR (French), de-DE (German), and zh-CN (Chinese).

• Options: It provides several options that could be used to format numbers.

Set the Locales and Options

Intl.NumberFormat provides several locales that you can set to customize how numbers are formatted. If you display any large number to a user in the US, then the number should be separated with a comma at every thousand. However, for a German user, it should be separated with a dot at every thousand, etc.

It also provides several options to format the number in a different style. Some of the options are given below:

• style: It’s the formatting style, the default is decimal. There are various styles, such as currency for current formatting, percent for percent formatting, and unit for unit formatting.

• notation: The default is standard. It could be scientific, engineering, and compact.

• currencyDisplay: This is used to display the currency in currency format. The default value is Symbol, which could be narrowSymbol, code, and name.

Advice: If you'd like to learn more about the options and locales, click here.

To set the options for formatting numbers, the object would be created like this:

let uscurrencyformatter = new Intl.NumberFormat("en-US", {
  style: "currency",
  currency: "USD",
});

The locale is set to en-US, and the style is currency, which formats the numbers in currency format. The currency is also defined as USD.

Using the format method

Once an instance of Intl.NumberFormat has been created and options and locales have been set, you can use the format method to format the numbers.

Here is an example:

let number = 987654321;
let formattedNumber = uscurrencyformatter.format(number);
console.log(formattedNumber);

// Output:
// $987,654,321.00

Above, you can see the 2 0's after the decimal. You can also handle them easily by using the minimumFractionDigits.

let uscurrencyformatter = new Intl.NumberFormat("en-US", {
  style: "currency",
  currency: "USD",
  minimumFractionDigits: 0,
});

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Examples

Let's see a few examples to add clarity!

Example 1:

Below, the same number is formatted in 3 different locales. The first is separated by commas, the second by dots, and the third by spaces.

let number = 987654321987;

let USformatter = new Intl.NumberFormat("en-US");
let USformattedNumber = USformatter.format(number);
console.log(USformattedNumber); // 987,654,321,987

let germanformatter = new Intl.NumberFormat("de-DE");
let DEformattedNumber = germanformatter.format(number);
console.log(DEformattedNumber); // 987.654.321.987

let frenchformatter = new Intl.NumberFormat("fr-FR");
let FRformattedNumber = frenchformatter.format(number);
console.log(FRformattedNumber); // 987 654 321 987

Example 2:

In this example, we have added the options. Here the notation is set to compact, which means the larger number will be formatted to a small notation like 1000000 will be formatted to 1M.

let options = {
  notation: "compact",
};

let number = 987654321987;

let USformatter = new Intl.NumberFormat("en-US", options);
let USformattedNumber = USformatter.format(number);
console.log(USformattedNumber); // 988B

let germanformatter = new Intl.NumberFormat("de-DE", options);
let DEformattedNumber = germanformatter.format(number);
console.log(DEformattedNumber); // 988 Mrd.

let frenchformatter = new Intl.NumberFormat("fr-FR", options);
let FRformattedNumber = frenchformatter.format(number);
console.log(FRformattedNumber); // 988 Md

Example 3:

In the following, the compact numbers are formatted in "K", "M", "B", and "T". If you change the compactDisplay to long, then "K" would be replaced by a thousand, "M" by Million, "B" by Billion, and "T" by Trillion.

let options = {
  notation: "compact",
  compactDisplay: "short",
};
function formatCmpctNumber(number) {
  const usformatter = Intl.NumberFormat("en-US", options);
  return usformatter.format(number);
}

console.log(formatCmpctNumber(-32)); // -32
console.log(formatCmpctNumber(999)); // 999
console.log(formatCmpctNumber(5678)); // 5.7K
console.log(formatCmpctNumber(230000)); // 230K
console.log(formatCmpctNumber(32333435)); // 32M
console.log(formatCmpctNumber(92351236547)); // 92B
console.log(formatCmpctNumber(12233445566778)); // 12T

Conclusion

In this article, we took a look at the JS Internationalization API and how to use it to format compact numbers. We also explored the Intl.NumberFormat object to format the compact numbers and how to use locales and options. Then at the end, we looked at some examples to clarify everything.