diff --git a/flutter_client/lib/cache/audio_cache_manager.dart b/flutter_client/lib/cache/audio_cache_manager.dart
index 9733eba9..34a4a061 100644
--- a/flutter_client/lib/cache/audio_cache_manager.dart
+++ b/flutter_client/lib/cache/audio_cache_manager.dart
@@ -96,13 +96,25 @@ class AudioCacheManager {
         .go();
   }
 
-  /// Total bytes used by the cache.
+  /// Total bytes used by the cache. Walks the cache directory directly
+  /// instead of summing the index, because the streaming-as-you-play
+  /// path (audio_handler's LockCachingAudioSource) writes files
+  /// without registering an index row. The index sum would always
+  /// understate (often to zero) for users who only stream.
   Future<int> usageBytes() async {
-    final result = await _db.customSelect(
-      'SELECT COALESCE(SUM(size_bytes), 0) AS total FROM audio_cache_index',
-      readsFrom: {_db.audioCacheIndex},
-    ).getSingle();
-    return result.read<int>('total');
+    final dir = Directory(await _tracksDir());
+    if (!await dir.exists()) return 0;
+    var total = 0;
+    await for (final entity in dir.list(followLinks: false)) {
+      if (entity is File) {
+        try {
+          total += await entity.length();
+        } catch (_) {
+          // Race against concurrent writes / deletes — just skip.
+        }
+      }
+    }
+    return total;
   }
 
   /// Evicts files until usage ≤ targetBytes. Eviction order: