The Italian island of Sardinia from Rome separates about 270 km. You can cross this distance by plane, which flies about 40 minutes and costs from 135 to 195 EUR. Or rent a car and use the ferry, which a passenger with a car will cost between 90-100 and above EUR, is about 5 hours from the port city of Civitavecchia. From there you will also need to get to the capital. It turns out to be quite hard, long and expensive, therefore it will not be possible to go from Sardinia to Rome on excursions and back in a day or two.

Therefore, if you really want to relax on the island and at the same time to visit the main attractions of the Eternal City, then you will need to plan the trip in a different way. It is best to first go to Rome, where to stay for a few days and inspect everything that you want, and then move by plane or ferry to the quiet and calm Sardinia, where to relax, swim and sunbathe in your own pleasure.