Formatting a Number With Exactly Two Decimals in JavaScript

Format number to always show 2 decimal places

(Math.round(num * 100) / 100).toFixed(2);

Live Demo

var num1 = "1";

document.getElementById('num1').innerHTML = (Math.round(num1 * 100) / 100).toFixed(2);

var num2 = "1.341";

document.getElementById('num2').innerHTML = (Math.round(num2 * 100) / 100).toFixed(2);

var num3 = "1.345";

document.getElementById('num3').innerHTML = (Math.round(num3 * 100) / 100).toFixed(2);

span {

    border: 1px solid #000;

    margin: 5px;

    padding: 5px;

}

<span id="num1"></span>

<span id="num2"></span>

<span id="num3"></span>

Formatting a number with exactly two decimals in JavaScript

To format a number using fixed-point notation, you can simply use the toFixed method:

(10.8).toFixed(2); // "10.80"

var num = 2.4;
alert(num.toFixed(2)); // "2.40"

Note that toFixed() returns a string.

IMPORTANT: Note that toFixed does not round 90% of the time, it will return the rounded value, but for many cases, it doesn't work.

For instance:

2.005.toFixed(2) === "2.00"

UPDATE:

Nowadays, you can use the Intl.NumberFormat constructor. It's part of the ECMAScript Internationalization API Specification (ECMA402). It has pretty good browser support, including even IE11, and it is fully supported in Node.js.

const formatter = new Intl.NumberFormat('en-US', {
   minimumFractionDigits: 2,      
   maximumFractionDigits: 2,
});

console.log(formatter.format(2.005)); // "2.01"
console.log(formatter.format(1.345)); // "1.35"

JavaScript math, round to two decimal places

NOTE - See Edit 4 if 3 digit precision is important

var discount = (price / listprice).toFixed(2);

toFixed will round up or down for you depending on the values beyond 2 decimals.

Example: http://jsfiddle.net/calder12/tv9HY/

Documentation: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number/toFixed

Edit - As mentioned by others this converts the result to a string. To avoid this:

var discount = +((price / listprice).toFixed(2));

Edit 2- As also mentioned in the comments this function fails in some precision, in the case of 1.005 for example it will return 1.00 instead of 1.01. If accuracy to this degree is important I've found this answer: https://stackoverflow.com/a/32605063/1726511 Which seems to work well with all the tests I've tried.

There is one minor modification required though, the function in the answer linked above returns whole numbers when it rounds to one, so for example 99.004 will return 99 instead of 99.00 which isn't ideal for displaying prices.

Edit 3 - Seems having the toFixed on the actual return was STILL screwing up some numbers, this final edit appears to work. Geez so many reworks!

var discount = roundTo((price / listprice), 2);

function roundTo(n, digits) {
  if (digits === undefined) {
    digits = 0;
  }

  var multiplicator = Math.pow(10, digits);
  n = parseFloat((n * multiplicator).toFixed(11));
  var test =(Math.round(n) / multiplicator);
  return +(test.toFixed(digits));
}

See Fiddle example here: https://jsfiddle.net/calder12/3Lbhfy5s/

Edit 4 - You guys are killing me. Edit 3 fails on negative numbers, without digging into why it's just easier to deal with turning a negative number positive before doing the rounding, then turning it back before returning the result.

function roundTo(n, digits) {
    var negative = false;
    if (digits === undefined) {
        digits = 0;
    }
    if (n < 0) {
        negative = true;
        n = n * -1;
    }
    var multiplicator = Math.pow(10, digits);
    n = parseFloat((n * multiplicator).toFixed(11));
    n = (Math.round(n) / multiplicator).toFixed(digits);
    if (negative) {
        n = (n * -1).toFixed(digits);
    }
    return n;
}

Fiddle: https://jsfiddle.net/3Lbhfy5s/79/

How to format numbers in javascript to two decimal digits?

.toFixed() converts your result to String,

so you need to make it back a Number: jsBin demo

parseFloat( num.toFixed(2) )

or by simply using the Unary +

+num.toFixed(2)

both will give the following:

//   15.00   --->   15
//   15.20   --->   15.2

If you only want to get rid of the .00 case, than you can go for String manipulation using .replace()

num.toFixed(2).replace('.00', '');

Note: the above will convert your Number to String.

JS - Format number with 2 decimal not rounded

(Math.floor(a * 100) / 100).toFixed(2);

With toFixed(2) !

JSFIDDLE DEMO

How to round to at most 2 decimal places, if necessary

Use Math.round() :

Math.round(num * 100) / 100

Or to be more specific and to ensure things like 1.005 round correctly, use Number.EPSILON :

Math.round((num + Number.EPSILON) * 100) / 100

Truncate number to two decimal places without rounding

Convert the number into a string, match the number up to the second decimal place:

function calc(theform) {

    var num = theform.original.value, rounded = theform.rounded

    var with2Decimals = num.toString().match(/^-?\d+(?:\.\d{0,2})?/)[0]

    rounded.value = with2Decimals

}

<form onsubmit="return calc(this)">

Original number: <input name="original" type="text" onkeyup="calc(form)" onchange="calc(form)" />

<br />"Rounded" number: <input name="rounded" type="text" placeholder="readonly" readonly>

</form>

How to parse float with two decimal places in javascript?

You can use toFixed() to do that

var twoPlacedFloat = parseFloat(yourString).toFixed(2)

Always display at least two decimal places

You could fix to 2 or the count of current places;

 var result = num.toFixed(Math.max(2, (num.toString().split('.')[1] || []).length));

How to make a number with proper commas round to exactly 2 decimal places?

You can do it like this

var formatter = new Intl.NumberFormat('en-US', {
  style: 'currency',
  currency: 'USD',
});
var num1 = 1000000.3
console.log(formatter.format(num1))

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