diff --git a/cara/apps/calculator/static/js/form.js b/cara/apps/calculator/static/js/form.js
index de32ed7d..d1f4b584 100644
--- a/cara/apps/calculator/static/js/form.js
+++ b/cara/apps/calculator/static/js/form.js
@@ -277,6 +277,30 @@ function validate_form(form) {
       submit = false;
   });
 
+  //Check if breaks length >= activity length
+  var button = document.getElementById("activity_breaks");
+  $(button).next('span').remove();
+
+  var lunch_mins = 0;
+  if (document.getElementById('lunch_option_yes').checked) {
+    var lunch_start = document.getElementById("lunch_start");
+    var lunch_finish = document.getElementById("lunch_finish");
+    lunch_mins = parseTimeToMins(lunch_finish.value) - parseTimeToMins(lunch_start.value);
+  }
+  
+  var coffee_breaks = parseInt(document.querySelector('input[name="coffee_breaks"]:checked').value);
+  var coffee_duration = parseInt(document.getElementById("break_duration").value);
+  var coffee_mins = coffee_breaks * coffee_duration;
+  
+  var activity_start = document.getElementById("activity_start");
+  var activity_finish = document.getElementById("activity_finish");
+  var activity_mins = parseTimeToMins(activity_finish.value) - parseTimeToMins(activity_start.value);
+
+  if ((lunch_mins + coffee_mins) >= activity_mins) {
+    insertSpanAfter(button, "Length of breaks >= Length of activity");
+    submit = false;
+  }
+
   return submit;
 }
 
@@ -341,6 +365,13 @@ function parseValToNumber(val) {
   return parseInt(val.replace(':',''), 10);
 }
 
+function parseTimeToMins(cTime)
+{
+  var d = new Date();
+  var time = cTime.match(/(\d+)(:(\d\d))?\s*(p?)/);
+  return parseInt(time[1]*60) + parseInt(time[3]);
+}
+
 /* -------On Load------- */
 $(document).ready(function () {
   // When the document is ready, deal with the fact that we may be here
diff --git a/cara/apps/calculator/templates/calculator.form.html.j2 b/cara/apps/calculator/templates/calculator.form.html.j2
index 2e33fbdc..2b4a6730 100644
--- a/cara/apps/calculator/templates/calculator.form.html.j2
+++ b/cara/apps/calculator/templates/calculator.form.html.j2
@@ -163,7 +163,7 @@
     </select><br>
     <hr width="80%">
 
-    <b>Activity breaks:</b><br>
+    <span id="activity_breaks"><b>Activity breaks:</b></span><br>
     <!-- Lunch Options -->
     Lunch break:&nbsp;&nbsp;
     <input type="radio" id="lunch_option_no" name="lunch_option" value=0 onclick="require_fields(this)" tabindex="0">
@@ -231,7 +231,7 @@
   Refer to <a href="/calculator/user-guide"> COVID Calculator user-guide </a> for more detailed explanations on how to use this tool. <br>
 </div>
 
-<button type='submit' tabindex="0">Generate report</button><br><br><br><br>
+<button type='submit' id="generate_report" tabindex="0">Generate report</button><br><br><br><br>
 </form>
 
 <!-- Dialog boxes -->