JSFiddle - React, Tailwind, and code Playground

HTML

<table border = "1" id = "table">
  <TR>
        <TH>Resource</TH> 
        <TH>Vacation</TH> <!-- Entered By User-->
        <TH>Allocation</TH> <!-- Entered By User-->
        <TH>Holidays</TH> <!-- Entered By User-->
        <TH>Capacity</TH>
        <TH>Remainder</TH>
    </TR>
  <tr>
  <td>$user.resource</td>

        <td><input type=text name="vacation" size="6" maxlength="10"></td>
        <td><input type=text name="alloc" size="6" maxlength="10"></td>
        <td><input type=text name="holidays" size="6" maxlength="10"></td>
        <td><input type=text name="capacity" size="6" maxlength="10"></td>
        <td><input type=text name="remainder" size="6" maxlength="10"></td>
    </tr>
  <tr>
  <td>Total:</td>
  <td></td><td></td><td></td>
  <td class= "capsum"><input type="text" name="captotal" size="6" maxlength="10"></td>
  <td><input type="text" name="remtotal" size="6" maxlength="10"></td>

  </tr>

  </table>

JavaScript

$('table#table input[name=capacity]').change(function()
{
 var sum = 0;

 $('table#table input[name=capacity]').each(function()
 {
  sum += parseInt($(this).val());
 });

 $('input[name=captotal]').val(sum);
});