How to Round a Number to 1 Decimal Place in Javascript

In this tutorial, you will learn how to round a number to 1 decimal place in javascript. It is very likely that we will have a number of digits after the decimal point when we do a specific computation and obtain a decimal number. As a result, rounding a number to a specified number of decimal places for readability is very standard. For a newbie developer, it can be a bit tricky to round a number to 1 decimal place.

There are numerous ways to round a number to 1 decimal place. 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 round a number to 1 decimal place 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 1 as a parameter. As a result, it will round the number to 1 decimal place.
  • We will display the result in the h1 element.
let btnGet = document.querySelector('button');
let result = document.querySelector('h1');

let num = 230.5253;

btnGet.addEventListener('click', () => {
    result.innerText = num.toFixed(1);
});