You can configure Miro to automatically stop seeding a completed download (via the Bittorrent protocol) after a certain upload ratio is reached:
- Click on File > Preferences > Downloads
- Check "Stop torrent upload when this ratio is reached" and enter a number
- Note that the default value is 2, which means that once you have upload the file for 200% of its size, the upload process shall stop.
- Close the Preferences window.