Travelling to Paris for just 7 days, but want to spend 2 days in Italy. what's the fastest way to get there

The distance between Paris & Rome is: Miles: 687.11 Kilometers: 1105.76 and the only practical way to do this is by airplane. Frankly, you'd waste so much time going to/from airports, plus the cost, that it would not be worthwhile, suggest that you need more time and should fly home out of your destination city. Once in Rome, you can easily travel by train to Florence and Venice. Consider making Italy at a different time, 2 days is hardly worth the time, expense and difficulty.

The fastest way to get there is obviously by plane. If you take the right flights on something like EasyJet you can make the flight for something like 100 euros or less round trip. The real question is why would you want to try to squeeze in a visit to Italy when you have such a limited amount of time? You've got to check out of your hotel, get to the airport, catch the flight, deplane, find your hotel in Italy, check in and get settled. that going to kill the better part of a day. Ditto on the way back. For what? So you can say you've been to Italy?