diff --git a/code/map_data_render.js b/code/map_data_render.js
index e4e1da36..d4ac2860 100644
--- a/code/map_data_render.js
+++ b/code/map_data_render.js
@@ -7,7 +7,7 @@ window.Render = function() {
 
   // when there are lots of portals close together, we only add some of them to the map
   // the idea is to keep the impression of the dense set of portals, without rendering them all
-  this.CLUSTER_SIZE = L.Browser.mobile ? 16 : 8;  // the map is divided into squares of this size in pixels for clustering purposes. mobile uses larger markers, so therefore larger clustering areas
+  this.CLUSTER_SIZE = L.Browser.mobile ? 10 : 4;  // the map is divided into squares of this size in pixels for clustering purposes. mobile uses larger markers, so therefore larger clustering areas
   this.CLUSTER_PORTAL_LIMIT = 4; // no more than this many portals are drawn in each cluster square
 
   // link length, in pixels, to be visible. use the portal cluster size, as shorter than this is likely hidden
@@ -15,6 +15,8 @@ window.Render = function() {
   this.LINK_VISIBLE_PIXEL_LENGTH = this.CLUSTER_SIZE;
 
   this.entityVisibilityZoom = undefined;
+
+  this.portalMarkerScale = undefined;
 }
 
 
@@ -426,6 +428,15 @@ window.Render.prototype.updateEntityVisibility = function() {
 
     this.resetPortalClusters();
     this.resetLinkVisibility();
+
+    if (this.portalMarkerScale === undefined || this.portalMarkerScale != portalMarkerScale()) {
+      this.portalMarkerScale = portalMarkerScale();
+
+      console.log('Render: map zoom '+map.getZoom()+' changes portal scale to '+portalMarkerScale()+' - redrawing all portals');
+
+      //NOTE: we're not calling this because it resets highlights - we're calling it as it resets the style (inc size) of all portal markers
+      resetHighlightedPortals();
+    }
   }
 }
 
diff --git a/code/portal_marker.js b/code/portal_marker.js
index 4507b699..5c5f9389 100644
--- a/code/portal_marker.js
+++ b/code/portal_marker.js
@@ -2,7 +2,10 @@
 // code to create and update a portal marker
 
 
-
+window.portalMarkerScale = function() {
+  var zoom = map.getZoom();
+  return zoom >= 14 ? 1 : zoom >= 11 ? 0.8 : zoom >= 8 ? 0.65 : 0.5;
+}
 
 // create a new marker. 'data' contain the IITC-specific entity data to be stored in the object options
 window.createMarker = function(latlng, data) {
@@ -35,11 +38,13 @@ window.setMarkerStyle = function(marker, selected) {
 
 
 window.getMarkerStyleOptions = function(details) {
-  var lvlWeight = Math.max(2, Math.floor(details.level) / 1.5);
-  var lvlRadius = details.team === window.TEAM_NONE ? 7 : Math.floor(details.level) + 4;
+  var scale = window.portalMarkerScale();
+
+  var lvlWeight = Math.max(2, Math.floor(details.level) / 1.5) * scale;
+  var lvlRadius = (details.team === window.TEAM_NONE ? 7 : Math.floor(details.level) + 4) * scale;
 
   var options = {
-    radius: lvlRadius + (L.Browser.mobile ? PORTAL_RADIUS_ENLARGE_MOBILE : 0),
+    radius: lvlRadius + (L.Browser.mobile ? PORTAL_RADIUS_ENLARGE_MOBILE*scale : 0),
     stroke: true,
     color: COLORS[details.team],
     weight: lvlWeight,
diff --git a/plugins/portal-highlighter-hide-team.user.js b/plugins/portal-highlighter-hide-team.user.js
index 1ae86d25..845cf418 100644
--- a/plugins/portal-highlighter-hide-team.user.js
+++ b/plugins/portal-highlighter-hide-team.user.js
@@ -22,7 +22,9 @@
 window.plugin.portalHighlighterHideOwnership = function() {};
 
 window.plugin.portalHighlighterHideOwnership.highlight = function(data) {
-  var params = {fillColor: COLORS[TEAM_NONE], color: COLORS[TEAM_NONE], opacity: 1, fillOpacity: 0.5, radius: 7+(L.Browser.mobile ? PORTAL_RADIUS_ENLARGE_MOBILE : 0), weight: 2};
+  var scale = window.portalMarkerScale();
+
+  var params = {fillColor: COLORS[TEAM_NONE], color: COLORS[TEAM_NONE], opacity: 1, fillOpacity: 0.5, radius: 7*scale+(L.Browser.mobile ? PORTAL_RADIUS_ENLARGE_MOBILE*scale : 0), weight: 2};
   data.portal.setStyle(params);
 }