diff --git a/weed/server/master_grpc_server_volume.go b/weed/server/master_grpc_server_volume.go
index 9f0adb4c9..9da947869 100644
--- a/weed/server/master_grpc_server_volume.go
+++ b/weed/server/master_grpc_server_volume.go
@@ -209,7 +209,7 @@ func (ms *MasterServer) Statistics(ctx context.Context, req *master_pb.Statistic
 
 	volumeLayout := ms.Topo.GetVolumeLayout(req.Collection, replicaPlacement, ttl, types.ToDiskType(req.DiskType))
 	stats := volumeLayout.Stats()
-	totalSize := ms.Topo.GetDiskUsages().GetMaxVolumeCount() * int64(ms.option.VolumeSizeLimitMB)
+	totalSize := ms.Topo.GetDiskUsages().GetMaxVolumeCount() * int64(ms.option.VolumeSizeLimitMB) * 1024 * 1024
 	resp := &master_pb.StatisticsResponse{
 		TotalSize: uint64(totalSize),
 		UsedSize:  stats.UsedSize,