<table class="table table-bordered">
   <thead>
      <tr>
        <th>Coût HT</th>
        <th>Marge</th>
        <th>Prix TTC</th>
      </tr>
   </thead>
   <tbody>
      <tr>
        <td align="center"><p id="totalcout"></p></td>
        <td align="center"><p id="marge">5</p></td>
        <td align="center"><p id="ttc"></p></td>
      </tr>
   </tbody>

// Addition when click checkbox
$("input[type=checkbox]").click(function(e) {
    var total = 0;
    $("input[type=checkbox]:checked").each(function() {
        total += parseFloat($(this).val());
    });
    if (total == 0) {
        $("#totalcout").html(0);
    } else {
        $("#totalcout").html(total + ' €');
    }
})