How to Set Decimal Places in Javascript

In this tutorial, you will learn how to set decimal places in javascript. It is very likely that there will be a large number of digits after the decimal point when we do a specific computation and return a decimal value. In order to make a number more readable, it is therefore quite standard practice to round it to a predetermined number of decimal places. For a newbie developer, it can be a bit tricky to set decimal places in a number.

There are numerous ways to set number decimal places in a number. We are going to use the simplest approach which involves the usage of the toFixed() method. It converts the number to string and rounds it to a specified number of decimals.

In the following example, we have one global variable that holds a number. Upon click of a button, we will set number to certain decimal places and display the result on the screen. Please have a look over the code example and the steps given below.

  • We have selected 2 elements (button and h1) using the document.querySelector() method and stored them in btn and result variables.
  • We have created a global variable num that holds a decimal number as a value.
  • We have added a click event listener to the button element.
  • We are executing the toFixed() method and passing 2 as a parameter. As a result, it will set the number to 2 decimal places.
  • We will display the result in the h1 element.
let btnGet = document.querySelector('button');
let result = document.querySelector('h1');

let num = 645.314255;

btnGet.addEventListener('click', () => {
    result.innerText = num.toFixed(2);
});