Format and Manipulate Numbers with Numeral.js

Often it is required that numbers are displayed in a formatted way, such as adding comma separation in long numeric values, plain old numbers with decimal places, percentages and so on. JavaScript doesn’t come with vast formatting options like most other high level languages.

I recently found out about Numeral.js, a JavaScript library for formatting and manipulating numbers. It also allows you to add locale and custom formats.


 Download the library from GitHub or link it using CDNJS. Alternatively, you can do “npm install numeral”.

Once you have added the dependency, create an instance of numeral. The constructor takes numbers or strings.

let testNumeral = numeral(10000);


>> 10,000 

Converting to Currency

testNumeral = numeral(10000);


>> $10,000.00

Converting to Bytes

testNumeral = numeral(1024);

testNumeral.format(' 0b');


Numeral.js is a great library and easy to use. If you want to learn more about it, check out the website for documentation and examples.

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