Question

Before anything you need to see the effect:

jsFiddle

As you can see it is a calculator where you can put a value anywhere and covert it to other values, but the problem is that i cant enter decimal int values like 0.3 or 0.999. What is the cause of this?

var id = {
    mm: 1,
    cm: 10,
    m: 1000,
    km: 1000000
};

$('input.bx').on('keyup', function() {

    var t = $(this).val();
    var i = id[$(this).attr("id")];
    var v = parseInt(t, 10);

    for (pp in id) {

        if (t !== '') {
            $("#" + pp).val(v / id[pp] * i);
        } else {
            $(".bx").val('');
        }

    }

});

<input type='text' class='bx' id='mm'> Milimeter<br>
<input type='text' class='bx' id='cm'> Centimeter<br>
<input type='text' class='bx' id='m'> Meter<br>
<input type='text' class='bx' id='km'> Kilometer<br> 

Answer 1

a working fiddle here

you have to use parseFloat and dont try to set the current focused element value cause you are over riding it while typing.