diff --git a/README.md b/README.md
index 8314185..3846246 100644
--- a/README.md
+++ b/README.md
@@ -77,6 +77,7 @@ start_time,length,rename_to
 * -f or --file          video file to split.
 * -s or --split-size    seconds to evenly split the videos
 * -e or --extra         extra optional options for ffmpeg, e.g. '-e -threads 8' to use 8 threads to speed up.
+* -S or --split-filesize    Split or chunk size in bytes (approximate). e.g -S 1048576 will split into files under 1 Megabyte
 
 #### Notes: