diff --git a/cara/apps/calculator/static/js/form.js b/cara/apps/calculator/static/js/form.js
index 835e6fda..de32ed7d 100644
--- a/cara/apps/calculator/static/js/form.js
+++ b/cara/apps/calculator/static/js/form.js
@@ -38,6 +38,18 @@ function require_fields(obj) {
       require_air_changes(false);
       require_air_supply(true);
       break;
+    case "hepa_yes":
+      require_hepa(true);
+      break;
+    case "hepa_no":
+      require_hepa(false);
+      break;
+    case "mask_on":
+      require_mask(true);
+      break;
+    case "mask_off":
+      require_mask(false);
+      break;
     case "event_type_single":
       require_single_event(true);
       require_recurrent_event(false);
@@ -52,18 +64,6 @@ function require_fields(obj) {
     case "lunch_option_yes":
       require_lunch(true);
       break;
-    case "mask_on":
-      require_mask(true);
-      break;
-    case "mask_off":
-      require_mask(false);
-      break;
-    case "hepa_yes":
-      require_hepa(true);
-      break;
-    case "hepa_no":
-      require_hepa(false);
-      break;
     default:
       break;
   }
@@ -218,8 +218,41 @@ function show_disclaimer() {
   }
 }
 
-function check_radio(id) {
-  $(id).click();
+$(".has_radio").on('click', function(event){
+  click_radio(this.id);
+});
+
+$(".has_radio").on('change', function(event){
+  click_radio(this.id);
+});
+
+function click_radio(id) {
+  switch (id) {
+    case "room_volume":
+      $("#room_type_volume").click();
+      break;
+    case "floor_area":
+    case "ceiling_height":
+      $("#room_type_dimensions").click();
+      break;
+    case "air_supply":
+      $("#air_type_supply").click();
+      break;
+    case "air_changes": 
+      $("#air_type_changes").click();
+      break;
+    case "hepa_amount":
+      $("#hepa_yes").click();
+      break;
+    case "single_event_date":
+      $("#event_type_single").click();
+      break;
+    case "recurrent_event_month":
+      $("#event_type_recurrent").click();
+      break;
+    default:
+      break;
+  }
 }
 
 /* -------Form validation------- */
diff --git a/cara/apps/calculator/templates/calculator.form.html.j2 b/cara/apps/calculator/templates/calculator.form.html.j2
index ef73ba12..4a52f5e9 100644
--- a/cara/apps/calculator/templates/calculator.form.html.j2
+++ b/cara/apps/calculator/templates/calculator.form.html.j2
@@ -43,12 +43,12 @@
     </div><br>
     <input type="radio" id="room_type_volume" name="volume_type" value="room_volume" onclick="require_fields(this)" required>
       <label for="room_type_volume">Room volume:</label> &nbsp;&nbsp; 
-    <input type="number" step="any" id="room_volume" class="non_zero" name="room_volume" placeholder="Room volume (m³)" min="0" onclick="check_radio('#room_type_volume')" ><br>
+    <input type="number" step="any" id="room_volume" class="non_zero has_radio" name="room_volume" placeholder="Room volume (m³)" min="0"><br>
     <input type="radio" id="room_type_dimensions" name="volume_type" value="room_dimensions" onclick="require_fields(this)" required>
       <label for="room_type_dimensions">Floor area:</label> &nbsp;&nbsp; 
-    <input type="number" step="any" id="floor_area" class="non_zero" name="floor_area" placeholder="Room floor area (m²)" min="0" onclick="check_radio('#room_type_dimensions')"><br>
+    <input type="number" step="any" id="floor_area" class="non_zero has_radio" name="floor_area" placeholder="Room floor area (m²)" min="0"><br>
     &nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <label for="room_type_dimensions">Ceiling height:</label> &nbsp;&nbsp; 
-    <input type="number" step="any" id="ceiling_height" class="non_zero" name="ceiling_height" placeholder="Room ceiling height (m²)" min="0" onclick="check_radio('#room_type_dimensions')"><br>
+    <input type="number" step="any" id="ceiling_height" class="non_zero has_radio" name="ceiling_height" placeholder="Room ceiling height (m²)" min="0"><br>
     <hr width="80%">
 
     <!-- Ventilation Options -->
@@ -66,10 +66,10 @@
     <div id="DIVmechanical_ventilation" style="display:none">
         <input type="radio" id="air_type_supply" name="mechanical_ventilation_type" value="air_supply" onclick="require_fields(this)">
           <label for="air_type_supply">Air supply flow rate</label> &nbsp;&nbsp; 
-        <input type="number" step="any" id="air_supply" class="non_zero" name="air_supply" min="0" placeholder="(m³ / hour)" onclick="check_radio('#air_type_supply')"><br>
+        <input type="number" step="any" id="air_supply" class="non_zero has_radio" name="air_supply" min="0" placeholder="(m³ / hour)"><br>
         <input type="radio" id="air_type_changes" name="mechanical_ventilation_type" value="air_changes" onclick="require_fields(this)">
           <label for="air_type_changes">Air changes per hour</label> &nbsp;&nbsp; 
-        <input type="number" step="any" id="air_changes" class="non_zero" name="air_changes" min="0" placeholder="(h⁻¹) only fresh air" onclick="check_radio('#air_type_changes')"><br>
+        <input type="number" step="any" id="air_changes" class="non_zero has_radio" name="air_changes" min="0" placeholder="(h⁻¹) only fresh air"><br>
     </div>
 
     <div id="DIVnatural_ventilation" style="display:none">
@@ -88,7 +88,7 @@
       <label for="hepa_no">No</label>&nbsp;&nbsp;
     <input type="radio" id="hepa_yes" name="hepa_option" value=1 onclick="require_fields(this)">
       <label for="hepa_yes">Yes</label>&nbsp;&nbsp;
-    <input type="number" step="any" id="hepa_amount" class="non_zero" name="hepa_amount" placeholder="(m³ / hour)" min="0" onclick="check_radio('#hepa_yes')">
+    <input type="number" step="any" id="hepa_amount" class="non_zero has_radio" name="hepa_amount" placeholder="(m³ / hour)" min="0">
     <hr width="80%">
 
     <b>Face masks:</b>
@@ -140,13 +140,13 @@
     <div data-tooltip="Select the date for one-off events or the month if the event is recurrent in the same space.">
         <span class="tooltip_text">?</span>
     </div><br>
-    <input type="radio" id="event_type_single" name="event_type" value="single_event" onclick="require_fields(this)" required>
+    <input type="radio" tabindex="-1" id="event_type_single" name="event_type" value="single_event" onclick="require_fields(this)" required>
       <label for="event_type_single">Single event</label> &nbsp;&nbsp;
       <label for="event_type_single">Date: </label>
-    <input type="text" id="single_event_date" class="datepicker" name="single_event_date" placeholder="dd/mm/yyyy" onclick="check_radio('#event_type_single')"><br>
-    <input type="radio" id="event_type_recurrent" name="event_type" value="recurrent_event" onclick="require_fields(this)" required>
+    <input type="text" id="single_event_date" class="datepicker has_radio" name="single_event_date" placeholder="dd/mm/yyyy"><br>
+    <input type="radio" tabindex="-1" id="event_type_recurrent" name="event_type" value="recurrent_event" onclick="require_fields(this)" required>
       <label for="event_type_recurrent">Recurrent usage</label>
-    <select id="recurrent_event_month" name="recurrent_event_month" onclick="check_radio('#event_type_recurrent')">
+    <select id="recurrent_event_month" name="recurrent_event_month" class="has_radio">
         <option value="January">January</option>
         <option value="February">February</option>
         <option value="March">March</option>