First, the rtorrent ratio settings explained:
First you have to enable the ratio settings in .rtorrent.rc by typing this line:
ratio.enable=
Next, rtorrent has a setting for a minimal ratio to reach AND a minimum uploaded size which it has to reach before the max.ratio action can take place:
ratio.min.set=XXX
and
ratio.upload.set=XXX
I want it to stop immediately, so I set them as low as possible.
Next you can set the max ratio to reach before it stops. I have set it to 1, which equals something like 0.001.
# Stop torrents when reaching upload ratio in percent,
# when also reaching total upload in bytes, or when
# reaching final upload ratio in percent.
ratio.enable=
ratio.min.set=0
ratio.max.set=1
ratio.upload.set=1b