diff --git a/Emby.Server.Implementations/Chapters/ChapterManager.cs b/Emby.Server.Implementations/Chapters/ChapterManager.cs
index a2d7d7d7fb..f24c975c14 100644
--- a/Emby.Server.Implementations/Chapters/ChapterManager.cs
+++ b/Emby.Server.Implementations/Chapters/ChapterManager.cs
@@ -108,7 +108,7 @@ public class ChapterManager : IChapterManager
             sum += chapters[i].StartPositionTicks - chapters[i - 1].StartPositionTicks;
         }
 
-        return sum / chapters.Count;
+        return sum / (chapters.Count - 1);
     }
 
     /// <inheritdoc />