diff --git a/src/main/java/org/operaton/fitpub/model/entity/ActivityMetrics.java b/src/main/java/org/operaton/fitpub/model/entity/ActivityMetrics.java
index 6d90219..99a1e5f 100644
--- a/src/main/java/org/operaton/fitpub/model/entity/ActivityMetrics.java
+++ b/src/main/java/org/operaton/fitpub/model/entity/ActivityMetrics.java
@@ -27,9 +27,15 @@ public class ActivityMetrics {
     @JoinColumn(name = "activity_id", nullable = false)
     private Activity activity;
 
+    /**
+     * Average speed in km/h (converted from m/s in FitParser/GpxParser).
+     */
     @Column(name = "average_speed", precision = 8, scale = 2)
     private BigDecimal averageSpeed;
 
+    /**
+     * Maximum speed in km/h (converted from m/s in FitParser/GpxParser).
+     */
     @Column(name = "max_speed", precision = 8, scale = 2)
     private BigDecimal maxSpeed;
 
diff --git a/src/main/java/org/operaton/fitpub/util/ParsedActivityData.java b/src/main/java/org/operaton/fitpub/util/ParsedActivityData.java
index e5fa745..d4558ca 100644
--- a/src/main/java/org/operaton/fitpub/util/ParsedActivityData.java
+++ b/src/main/java/org/operaton/fitpub/util/ParsedActivityData.java
@@ -49,6 +49,7 @@ public class ParsedActivityData {
         private Integer heartRate;
         private Integer cadence;
         private Integer power;
+        /** Speed in km/h (converted from m/s in FitParser/GpxParser). */
         private BigDecimal speed;
         private BigDecimal temperature;
         private BigDecimal distance;
diff --git a/src/main/resources/static/js/fitpub.js b/src/main/resources/static/js/fitpub.js
index 261db8e..89dfa8c 100644
--- a/src/main/resources/static/js/fitpub.js
+++ b/src/main/resources/static/js/fitpub.js
@@ -194,8 +194,8 @@ function createActivityMap(containerId, geoJsonData, options = {}) {
                             popupContent += `<strong>Heart Rate:</strong> ${props.heartRate} bpm<br>`;
                         }
                         if (props.speed !== undefined) {
-                            const speedKmh = props.speed * 3.6;
-                            popupContent += `<strong>Speed:</strong> ${speedKmh.toFixed(2)} km/h<br>`;
+                            // Speed is already in km/h from backend (converted in FitParser)
+                            popupContent += `<strong>Speed:</strong> ${props.speed.toFixed(2)} km/h<br>`;
                         }
                         if (props.elevation !== undefined) {
                             popupContent += `<strong>Elevation:</strong> ${props.elevation.toFixed(1)} m<br>`;
diff --git a/src/main/resources/templates/activities/detail.html b/src/main/resources/templates/activities/detail.html
index 8b3ab4e..7e7caa7 100644
--- a/src/main/resources/templates/activities/detail.html
+++ b/src/main/resources/templates/activities/detail.html
@@ -487,9 +487,10 @@
                     }
 
                     // Additional Metrics (conditional)
+                    // Note: averageSpeed is already in km/h from backend (converted in FitParser)
                     if (activity.averageSpeed) {
                         document.getElementById('metricAvgSpeedContainer').style.display = 'block';
-                        document.getElementById('metricAvgSpeed').textContent = (activity.averageSpeed * 3.6).toFixed(1) + ' km/h';
+                        document.getElementById('metricAvgSpeed').textContent = parseFloat(activity.averageSpeed).toFixed(1) + ' km/h';
                     }
                     if (activity.averageHeartRate) {
                         document.getElementById('metricAvgHRContainer').style.display = 'block';