[FFmpeg-user] help please

[sarkis yol]

hey what is the best way to hardcore subtitles into a movie while staying as close as possible to his original size and settings i tried this command:
ffmpeg -i 1.mp4 -vf "subtitles=1.srt:force_style='FontName=Droid Naskh Shift Alt,Fontsize=21'" -c:a copy "output.mp4"


but my 770mb movie goes to 1.3gb which is too much

even though i tried another movie and went from 750 to 800 mb which is good
but now allot of movies are getting x2 the size any help lease :)