diff --git a/make_cover_briefs.lua b/make_cover_briefs.lua
index 6369d5a..b7c744b 100755
--- a/make_cover_briefs.lua
+++ b/make_cover_briefs.lua
@@ -279,7 +279,7 @@ local estimate_time_required = function(books)
   for name, data in pairs(books) do
     local function loop()
       if data.cover_brief_file then return end
-      sum = sum + 60 * (1.5 + data.extracted_file_size/(config.llm_covers.maximum_bytes/7.5))
+      sum = sum + 60 * (1.5 + data.extracted_file_size/(config.llm_covers.maximum_bytes/6))
       count = count + 1
     end
     loop()