diff --git a/cara/apps/calculator/templates/calculator.form.html.j2 b/cara/apps/calculator/templates/calculator.form.html.j2
index 9b73d9fd..57adeeff 100644
--- a/cara/apps/calculator/templates/calculator.form.html.j2
+++ b/cara/apps/calculator/templates/calculator.form.html.j2
@@ -188,7 +188,7 @@
           <label for="mech_type_air_supply" class="col-form-label ml-2">Air supply flow rate</label>
           </div>
           <div>
-          <input type="number" step="any" id="air_supply" class="non_zero form-control" name="air_supply" min="0" placeholder="(m³ / hour)" data-has-radio="#mech_type_air_supply"><br>
+          <input type="number" step="any" id="air_supply" class="non_zero form-control" name="air_supply" min="0" placeholder="Flow rate (m³ / hour)" data-has-radio="#mech_type_air_supply"><br>
           </div>
         </div>
         <div class="split">
@@ -197,7 +197,7 @@
           <label for="mech_type_air_changes" class="col-form-label ml-2">Air changes per hour</label>
           </div>
           <div>
-          <input type="number" step="any" id="air_changes" class="non_zero form-control" name="air_changes" min="0" placeholder="(h⁻¹) only fresh air" data-has-radio="#mech_type_air_changes"><br>
+          <input type="number" step="any" id="air_changes" class="non_zero form-control" name="air_changes" min="0" placeholder="Air exchange (h⁻¹)" data-has-radio="#mech_type_air_changes"><br>
           </div>
         </div>
     </div>
@@ -205,11 +205,11 @@
     <div id="DIVnatural_ventilation" class="tabbed" style="display:none">
       <div class="split">
         <div><label class="col-form-label">Number of windows:</label></div>
-        <div><input type="number" id="windows_number" class="non_zero form-control" name="windows_number" min="1"><br></div>
+        <div><input type="number" id="windows_number" class="non_zero form-control" name="windows_number" placeholder="Number (#)" min="1"><br></div>
       </div>
       <div class="split">
         <div><label class="col-form-label">Height of window: </label></div>
-        <div><input type="number" step="any" id="window_height" class="non_zero form-control" name="window_height" placeholder="meters" min="0"><br></div>
+        <div><input type="number" step="any" id="window_height" class="non_zero form-control" name="window_height" placeholder="Height (m)" min="0"><br></div>
       </div>
         <div class='sub_title'>Window type:</div>
         <input class="ml-2" type="radio" id="window_sliding" name="window_type" value="window_sliding" onclick="require_fields(this)" checked="checked">
@@ -218,11 +218,11 @@
           <label for="window_hinged">Top- or Bottom-Hung</label><br>
         <div class="split">
           <div><label class="col-form-label">Width of window: </label></div>
-          <div><input type="number" step="any" id="window_width" class="non_zero disabled form-control" name="window_width" placeholder="meters" min="0" data-has-radio="#window_hinged"><br></div>
+          <div><input type="number" step="any" id="window_width" class="non_zero disabled form-control" name="window_width" placeholder="Width (m)" min="0" data-has-radio="#window_hinged"><br></div>
         </div>
         <div class="split">
           <div><label class="col-form-label">Opening distance: </label></div>
-          <div><input type="number" step="any" id="opening_distance" class="non_zero form-control" name="opening_distance" placeholder="meters" min="0"><br></div>
+          <div><input type="number" step="any" id="opening_distance" class="non_zero form-control" name="opening_distance" placeholder="Opening distance (m)" min="0"><br></div>
         </div>
         <div class='sub_title'>Window open:</div>
         <div class="form-group row">
@@ -247,7 +247,7 @@
       <label for="hepa_yes" class="col-form-label ml-2">Yes</label>
     </div>
     <div>
-    <input type="number" step="any" id="hepa_amount" class="non_zero disabled form-control" name="hepa_amount" placeholder="(m³ / hour)" min="0" data-has-radio="#hepa_yes">
+    <input type="number" step="any" id="hepa_amount" class="non_zero disabled form-control" name="hepa_amount" placeholder="Flow rate (m³ / hour)" min="0" data-has-radio="#hepa_yes">
     </div>
     </div>
     <hr width="80%">
@@ -285,7 +285,7 @@
 
     <div class="form-group row">
       <div class="col-sm-4"><label class="col-form-label">Total number of occupants:</label></div>
-      <div class="col-sm-6 align-self-center"><input type="number" id="total_people" class="form-control" name="total_people" min=1 required></div>
+      <div class="col-sm-6 align-self-center"><input type="number" id="total_people" class="form-control" name="total_people" placeholder="Number (#)" min=1 required></div>
     </div>
 
     <div class="form-group row">