Calculate price excluding tax doesn't give the exact price

Question

I'd like to calculate price excluding tax in real time like this :

Price included taxe (priceTi) = 550

TaxRate = 10 %

Price excluding tax (priceTe) should be = 500

The problem is that I get priceTe = 499.99999999999994

$(document).on('keyup', "#priceTi", function () {

    var priceTe = $('#priceTe');
    var taxRate = $('#taxRate');
    var priceTi = $('#priceTi');

    if (taxRate.val() != "") {
        value = this.value.replace(/,/g, '.');
        var tax = parseFloat((taxRate.val()/100) + 1) ;

        $('#priceTe').val(parseFloat(value) / tax ) ;

        return false;
    }
});

Welcome to the j̶o̶y̶ pain that is floating point numbers. You'll can use `toFixed()` to solve the problem. — Rory McCrossan, Nov 21 '16 at 17:03
http://stackoverflow.com/questions/588004/is-floating-point-math-broken — epascarello, Nov 21 '16 at 17:03

score 1 · Accepted Answer · answered Nov 21 '16 at 17:02

1

By using .toFixed(2) you can get the desired result.

$(document).on('keyup', "#priceTi", function () {

    var priceTe = $('#priceTe');
    var taxRate = $('#taxRate');
    var priceTi = $('#priceTi');

    if (taxRate.val() != "") {
        value = this.value.replace(/,/g, '.');
        var tax = parseFloat((taxRate.val()/100) + 1) ;

        $('#priceTe').val(parseFloat(value) / tax ).toFixed(2) ;

        return false;
    }
});

You can also round the to the nearest integer by using round. .49 will be rounded down, .5 will be rounded up. This function is Math.round(int)

answered Nov 21 '16 at 17:02

Mike

1,436
9
16

I have tried with toFixed(2) but it alwyas give 499.99999999999994 – hous Nov 21 '16 at 17:12
Given your numbers, you should get 495.00 – Mike Nov 21 '16 at 17:17
It works now but toFixed() should be inside val() ;) like this $('#priceTe').val(parseFloat((value) / tax).toFixed() ) ; – hous Nov 21 '16 at 17:21

Calculate price excluding tax doesn't give the exact price

1 Answers1