SO - 18700249

by Arun P Johny

HTML

<input id="total" readOnly /> <br />
<input class="field"/>
<input class="field"/>
<input class="field"/>

JavaScript

function TotalAmount(field, container) {
    var total = 0;
    field.each(function () {
        total += (parseFloat($(this).val()) || 0);
    });
    container.val(total == parseInt(total) ? total : total.toFixed(2));
}

var $fields = $('.field'), $ct = $('#total');

$fields.on('keyup change', function(){
    TotalAmount($fields, $ct)
})