JSFiddle - React, Tailwind, and code Playground
HTML
<form id='myform' method='post' action=''>
<table id='mytable'>
<tr>
<td></td>
<td></td>
<td>
<input type='checkbox' name='mycheckbox' class='mycheckbox' />
<input type='checkbox' name='mycheckbox2' class='mycheckbox'/>
</td>
<tr>
<tr>
<td class="Total">Total Checked</td>
<td class="TotalCount"></td>
</tr>
</table>
</form>
JavaScript
$(".mycheckbox").change(function () {
$(".TotalCount").text($(".mycheckbox:checked").length);
})