The line Airport - Roma Termini (and back) runs every 30 minutes; the travel lasts about 30 minutes, the ticket costs 11,00 euro; tickets can be bought at station counters and at newspaper kiosks in Termini and Fiumicino.
Warning: The train from Termini
to Fiumicino leaves from track 26 or 27, which are quite far from
the station entrance; we advise to take ten minutes more into
account.
The line Airport - Roma Tiburtina (and back) runs every 20 minutes; the travel lasts about 45 minutes, the ticket costs 5,50 euro.