User:DeletedUser010919/Sandbox5

   <script>
   function calculate() {
     var HP = document.getElementById('HP').value;
     var STR = document.getElementById('STR').value;
     var PTNCY = document.getElementById('PTNCY').value / 100;
     var PTNCYB = document.getElementById('PTNCYB').value / 100 + 1;
     var COBUFF = document.getElementById('COBUFF').value / 100 + 1;
     if (document.getElementById('ELEM').checked) {
       var EBUFF = 1.2;
     } else {
       var EBUFF = 1;
     }
     var TARG = document.getElementById('RAID').value;
     if (checkbox.checked) {
       var DUR = document.getElementById('DUR').value;
       var FREQ = document.getElementById('FREQ').value;
       var REGEN = document.getElementById('REGEN').value / 100;
       var TIMES = Math.floor(DUR/FREQ);
       var RTOTAL = (((0.65*HP + 0.2*STR) * REGEN * PTNCYB * COBUFF) / TARG) * EBUFF * TIMES;
       var TOTAL = (((0.65*HP + 0.2*STR) * PTNCY * PTNCYB * COBUFF) / TARG) * EBUFF + RTOTAL;
     } else {
       var TOTAL = (((0.65*HP + 0.2*STR) * PTNCY * PTNCYB * COBUFF) / TARG) * EBUFF;
     }
     document.getElementById("total").innerHTML = Math.floor(TOTAL);
     console.log(RTOTAL);
   }
   function display() {
     var hot = document.getElementById("HOT");
     if (document.getElementById('checkbox').checked) {
       hot.style.display = "block";
     } else {
       hot.style.display = "none";
     }
   }
   </script>

HP: <input type="number" id="HP" class="a">

STR: <input type="number" id="STR" class='a'>

PTNCY%: <input type="number" id="PTNCY" class='a'>

PTNCYB%: <input type="number" id="PTNCYB" class='a'>

COBUFF%: <input type="number" id="COBUFF" class='a'>

Same Element?: <input type="checkbox" id="ELEM"> Check for yes.

Characters to Heal: <input type= "number" id="RAID" class='a'>

Include Healing Over Time?<input type="checkbox" id="checkbox" onclick="display()">Check for yes.

REGEN%: <input type="number" id="REGEN" class='a'>

DURATION: <input type="number" id="DUR"class='a'>

HEAL FREQUENCY: <input type="number" id="FREQ"class='a'>

Total Heal:

   <button onclick="calculate()">
     Calculate
   </button>