Test Page

<form id="calc-form">

 <label>
   <input type="checkbox" class="calc-checkbox" value="10"> Option 1
 </label>

 <label>
   <input type="checkbox" class="calc-checkbox" value="20"> Option 2
 </label>

 <label>
   <input type="checkbox" class="calc-checkbox" value="30"> Option 3
 </label>

 Total: 0

</form>