diff --git a/public_html/config.js b/public_html/config.js
index be51699..1a486ff 100644
--- a/public_html/config.js
+++ b/public_html/config.js
@@ -125,3 +125,8 @@ BingMapsAPIKey = null;
 // This is not polished yet (and so is disabled by default),
 // currently it's just a data dump of the new fields with no UX work.
 ExtendedData = false;
+
+DefaultMaxAltitudeFilter = 65000
+DefaultMinAltitudeFilter = 0
+DefaultMaxSpeedFilter = 1000
+DefaultMinSpeedFilter = 0
\ No newline at end of file
diff --git a/public_html/index.html b/public_html/index.html
index 215bc5b..926caca 100644
--- a/public_html/index.html
+++ b/public_html/index.html
@@ -220,7 +220,7 @@
 								</div> <!-- dump1090_infoblock -->
 
 								<div class="config_button_row">
-									<button id="filter_button" class="config_button">Filters</button>
+									<button id="filter_button" class="config_button">Filters (<span id="active_filter_count">0</span>)</button>
 									<button id="column_select_button" class="config_button">Select Columns</button>
 								</div>
 
diff --git a/public_html/script.js b/public_html/script.js
index 82fe525..1543360 100644
--- a/public_html/script.js
+++ b/public_html/script.js
@@ -52,6 +52,8 @@ var NBSP='\u00a0';
 var layers;
 var layerGroup;
 
+var ActiveFilterCount = 0;
+
 var altitude_slider = null;
 var speed_slider = null;
 
@@ -306,8 +308,8 @@ function initialize() {
                 start: [0, 65000],
                 connect: true,
                 range: {
-                    'min': 0,
-                    'max': 65000
+                    'min': DefaultMinAltitudeFilter,
+                    'max': DefaultMaxAltitudeFilter
                 },
                 step: 25,
                 format: {
@@ -342,8 +344,8 @@ function initialize() {
                 start: [0, 1000],
                 connect: true,
                 range: {
-                    'min': 0,
-                    'max': 1000
+                    'min': DefaultMinSpeedFilter,
+                    'max': DefaultMaxSpeedFilter
                 },
                 step: 5,
                 format: {
@@ -1168,6 +1170,7 @@ function refreshSelected() {
         $('#dump1090_total_ac').text(TrackedAircraft);
         $('#dump1090_total_ac_positions').text(TrackedAircraftPositions);
         $('#dump1090_total_history').text(TrackedHistorySize);
+        $('#active_filter_count').text(ActiveFilterCount);
 
         if (MessageRate !== null) {
                 $('#dump1090_message_rate').text(MessageRate.toFixed(1));
@@ -2193,6 +2196,13 @@ function updatePlaneFilter() {
 
     PlaneFilter.aircraftTypeCode = aircraftTypeCode;
     PlaneFilter.aircraftIdent = aircraftIdent;
+
+    var altitudeFilterSet = (PlaneFilter.minAltitude == DefaultMinAltitudeFilter && PlaneFilter.maxAltitude == DefaultMaxAltitudeFilter) ? 0 : 1;
+    var speedFilterSet = (PlaneFilter.minSpeedFilter == DefaultMinSpeedFilter && PlaneFilter.maxSpeedFilter == DefaultMaxSpeedFilter) ? 0 : 1;
+    var aircraftTypeFilterSet = (PlaneFilter.aircraftTypeCode == undefined) ? 0 : 1;
+    var aircraftIdentFilterSet = (PlaneFilter.aircraftIdent == undefined) ? 0 : 1;
+
+    ActiveFilterCount = altitudeFilterSet + speedFilterSet + aircraftTypeFilterSet + aircraftIdentFilterSet;
 }
 
 function refreshDataSourceFilters () {