diff --git a/resources/settings/properties.xml b/resources/settings/properties.xml
index 7f4ab65..a0d28f2 100644
--- a/resources/settings/properties.xml
+++ b/resources/settings/properties.xml
@@ -8,4 +8,5 @@
     <property id="showNextPoint" type="boolean">true</property>
     <property id="saveToFit" type="boolean">true</property>
     <property id="tlFieldData" type="number">1</property>
+    <property id="rollingAvgWindow" type="number">5</property>
 </properties>
diff --git a/resources/settings/settings.xml b/resources/settings/settings.xml
index 355fa4c..ea9cd01 100644
--- a/resources/settings/settings.xml
+++ b/resources/settings/settings.xml
@@ -36,4 +36,7 @@
     <setting propertyKey="@Properties.saveToFit" title="@Strings.SaveToFit">
         <settingConfig type="boolean" />
     </setting>
+    <setting propertyKey="@Properties.rollingAvgWindow" title="@Strings.RollingAvgWindow">
+        <settingConfig type="numeric" />
+    </setting>
 </settings>
\ No newline at end of file
diff --git a/resources/strings/strings.xml b/resources/strings/strings.xml
index 152874e..178f4fe 100644
--- a/resources/strings/strings.xml
+++ b/resources/strings/strings.xml
@@ -16,6 +16,7 @@
     <string id="TLFGrade">Grade</string>
     <string id="TLFGAP">Grade Adjusted Pace</string>
     <string id="TLFVSpeed">Vertical Speed</string>
+    <string id="RollingAvgWindow">Rolling average window (~seconds)</string>
     <string id="uGrade">%</string>
     <string id="uGAP">min/km</string>
     <string id="uVSpeed">m/min</string>
diff --git a/source/RepaFieldView.mc b/source/RepaFieldView.mc
index 882b7fe..855c0fb 100644
--- a/source/RepaFieldView.mc
+++ b/source/RepaFieldView.mc
@@ -55,6 +55,7 @@ class RepaFieldView extends WatchUi.DataField {
     hidden var speedNotPace as Boolean;
     hidden var showNextPoint as Boolean;
     hidden var tlFieldData as Number;
+    hidden var rollingAvgWindow as Number = 5;
     hidden var hrZones as Array<Number>;
     hidden var hrHist as Array<Number>;
     hidden var hrZoneColors as Array<Number>;
@@ -129,8 +130,6 @@ class RepaFieldView extends WatchUi.DataField {
     function initialize() {
         DataField.initialize();
 
-        var RASize = 5; // TODO: rolling average window size => settings
-
         themeColor = Application.Properties.getValue("themeColor").toNumberWithBase(16);
         themeColor2 = Application.Properties.getValue("themeColor2").toNumberWithBase(16);
         themeColor3 = Application.Properties.getValue("themeColor3").toNumberWithBase(16);
@@ -138,6 +137,7 @@ class RepaFieldView extends WatchUi.DataField {
         speedNotPace = Application.Properties.getValue("speedNotPace");
         showNextPoint = Application.Properties.getValue("showNextPoint");
         tlFieldData = Application.Properties.getValue("tlFieldData").toNumber();
+        rollingAvgWindow = Application.Properties.getValue("rollingAvgWindow").toNumber();
 
         hrValue = 0;
         ahrValue = 0;
@@ -170,9 +170,9 @@ class RepaFieldView extends WatchUi.DataField {
         cgrade = null;
         cvspeed = null;
         cgap = null;
-        deltaAlt = new RollingAverage(RASize);
-        deltaDist = new RollingAverage(RASize);
-        deltaTime = new RollingAverage(RASize);
+        deltaAlt = new RollingAverage(rollingAvgWindow);
+        deltaDist = new RollingAverage(rollingAvgWindow);
+        deltaTime = new RollingAverage(rollingAvgWindow);
 
         var settings = System.getDeviceSettings();
         isDistanceMetric = settings.distanceUnits == System.UNIT_METRIC;