SO - 22610080

by Arun P Johny

HTML

<div id="collapseOne">
    <span id="col1">0</span> / <span class="max">3</span>
    <span class="custom-checkbox addspace pull-left">
        <input type="checkbox" value=""/>
        <span class="box"><span class="tick"></span></span>
    </span>
</div>

JavaScript

var max = 3;
var checkboxes = $("#collapseOne input[type=checkbox]");
checkboxes.change(function(){
    var current = checkboxes.filter(':checked').length;
    $( "#col1" ).text(current) ;
    checkboxes.filter(':not(:checked)').prop('disabled', current >= max);
});