Two and a half week trip to Scenic Europe - Need advice in planning

I fear a family of 4 not-light packers will find the trunk capacity of the typical European rental car a challenge. Between Venice, Florence and Rome a train will be a great deal faster than a car, and there will be no parking concerns. I don't think many people (possibly none) will recommend driving to the Cinque Terre or the Amalfi Coast, either.

Zurich is a perfectly attractive city, but people generally go to Switzerland for the scenery. You'll pay a pretty penny for any mainstream lodging in Switzerland. Take a look on booking.com for some random June dates and ask yourself whether you're willing to pay those prices for Zurich, as opposed to places in the Alps.

There's high demand for lodging in two areas of Italy you didn't mention, but which might be considered as alternatives to Switzerland: the Dolomites and the lakes. You didn't say anything about budget concerns, so costs may not be an issue for you. I had to pay more than I wanted to on Lake Como and in Bolzano (in a valley near the Dolomites) in early September. I'm sure mountain villages in the Dolomites as well as in Switzerland are also challenging. It would be smart to nail down reservations in places like that as soon as you can.

I'd try to condense the area you're trying to cover so you don't spend so much time in cars/trains/buses. I sort of feel like you'd do better to limit yourself to two of the three major areas you've mentioned--Paris, Italy and Austria/Switzerland. Keep in mind that with four travelers, there's likely to be at least one person who's basically non-functional on your arrival day, and your last day will be about getting packed and to the airport for the trip home. That means an "18-day" trip really gives you 16 fully usable days. The Venice-Florence-Rome trio could chew up close to 10 of those--or more, of course; Rome, especially, has so many things to see.

Planning a family-of-four trip to Europe

Presumably 2 of the 4 are the children? Ages would be helpful to know to have some idea of how mobile (or encumbered) you might be.

How fast the group can move will affect just how many places you could reasonably fit in

Keep in mind if you decide to rent a car that it is EXTREMELY expensive to pick up a rental in one country and drop off in another. There are also a variety of potential additional costs such as tolls and some cities have zones that you can't drive in without getting a hefty fine (and in some you simply will not want to drive, traffic is terrifying). You'll also likely need to get an IDP (a translation of your driver license) - not expensive but something you should plan. For those reasons, many in this forum would recommend trains or planes for your situation.

Fly open jaw (in to your city, home from your last) to save backtracking given your short time. Every time you change locations you lose about half a day to travel, especially if you're flying (getting to airport, through security, checking bags, etc.). It is often quite helpful to write out your plans showing the number of nights and indicating travel days so you can visualize how much time you'd actually have to see things. Remember you lose a day going to Europe and your last day is travel home. In your tentative plan above (Paris 3, Switzerland 7, Italy 6) it could look something like this (BTW I am not suggesting this is a good itinerary, just an example of how to plot it out):

Day 1 fly to Paris (typically overnight flight)
Day 2 arrive Paris (stay in Paris)
Day 3 Paris
Day 4 Paris a.m., fly to Zurich (stay in Zurich)
Day 5 - 6 - 7 - 8 - 9 Switzerland (whatever you decide to see given time of year)
Day 10 Fly to Venice a.m., Venice p.m. (stay in Venice)
Day 11 Venice
Day 12 Venice a.m. train to Florence, Florence p.m. (stay in Florence)
Day 13 Florence
Day 14 Florence a.m. train to Rome, Rome p.m. (stay in Rome)
Day 15 Rome
Day 16 flight home to USA (usually in the morning)

Best of luck.

mikep,
Just fyi, Vatican City is within the Roma perimeter, so just takes bus or taxi there from your hotel. Visiting there will probably take up the greater part of a day (the huge magnificent church and the museum for sure, plus possible crowds to negotiate through). With 3 days in Rome, you have the Vatican one day, and two days for (pick among them), the Colisseum, the Forum, the catacombs, the Appian Way, Capitoline Museum (giant statuary), various locations with Michelanglo sculptures, several outstanding churches (e.g. St.Peter in Chains, St. John Lateran, Santa Maria Maggiore), plus the neighborhoods for the ambience and the FOOD. There are lots more places, but you would want to do some research to see which places appeal to you. By the way, I believe you need to preorder tickets to the Vatican Museum.
And having a car in Rome is a real pain, not just with the crazy driving, but the parking also. The suggestion for using trains in Italy is a good one. And I concur with acraven about fitting 4 people and 4 not-small pieces of luggage plus (maybe) 4 backpack size items in a family sized sedan is not going to be comfortable. (I speak from experience, and we all had small carry-on sized bags.)

As acraven said, the Cinque Terra and Amalfi Coast just won't fit into your time frame, unless you drop someplace else.

Florence, with a side trip to Pisa one of your days there, should have two full days. One for Pisa, and one for the architectural beauties of Florence, plus the Ponte Vecchio. Since you aren't interested much in art, I haven't allowed time for that, but the Uffizi Gallery is a treasure box of Renaissance art, and the Accademia, of course, has Michaelangelo's David. So, if they are of interest to you, you may need to add another day there. (This implies a relatively fast pace of activity).

I haven't touched on your Switzerland, Austria or Paris days. (For me, I would shorten my time in Switzerland due to costs and IMO similarity of places, and add a day or two to Paris. But that is just me.) Check out travel options (train schedules, etc.) to see if your plans will work out and plan your itinerary with that in mind. And do try to pack as lightly as possible. You will get tired of schlepping bags over cobblestone walks and up stairs. Even if you drive from place to place, your walk from where the car is parked may be a bit of a trek. Medieval towns and cities do not usually have parking lots attached to hotels as in the US, unless you are in a modern chain hotel in a modern part of town, probably on the outskirts. And many cities and towns in Italy have ZTLs, zones where you cannot drive without getting a very expensive ticket.

I am curious as to why only Paris is on your list for France. Time constraints? Paris has tons of varied things rto see and do within all your options.

My last tip. Count nights, not days. You will find it more practical. As others have said before, 2 nights equals one full day. Give it a try. You will find it more useful. It is also important to calculate travel time between cities. Not just train or drive time, but checking out of lodgings, getting to the airport/train station/highway, and getting to your lodgings in the new location, checking in, dropping bags, etc. It all adds up. Lots to think about!

Best of luck! Enjoy yourselves!)

Thank you @acraven, @joe32F and @CL.

We are a family of four, two in late 40s and 50s and two in early 20s. Regarding trunk capacity, I see from rental car sites that some SUV and "Estate" type cars are available that can take 3 large and 3 small bags. I assume they mean the standard bag sizes - large being about 32 x 18 x 12 inch and small being 24 x 14 x 9 inch. If so, we can manage within these. I see that Paris and Switzerland in June would need warm clothes at least in the evenings - and with three ladies in the family, we would need big bags. But it's better to confirm exact trunk size from the car company before booking - I get that.

Thanks for your tips on car rentals, @CL. By renting a car, we were looking for convenience (stop where you want to for photo-ops or visit a tourist spot by taking a short detour that cannot be done in a train journey) and for a cheaper option (can stay away from expensive city hotels, might be cheaper than four bus/train tickets?? and avoid hassle of renting on a daily basis for local visits). We do not intend to drop off in another country, so that's out, but I understand the parking problem within a city. Overall - would it be really cheaper or similar compared to taking public transport between cities and for local visits and renting accommodation close to such public transport. The answer to this question would probably be the clincher. Not thinking of renting a car in Paris (if we go there), but considering it for Italy and Switzerland/ Austria. Based on your inputs, I see that renting a car may not be a good idea, but don't want to drop it just yet. I think that airplanes would be a lot more expensive than trains and buses and for the distances that we are looking at, will not save much on time too. Based on @acraven's view, will leave out Cinque Terre and the Amalfi Coast.

Staying in Zurich is not a requirement. Will look to stay in the Alps if that's a lot cheaper. Perhaps just a day or two in Zurich after we arrive. By the way, cost IS an issue. We are looking for cheap and good options. Among Swiss Alps, Austrian Alps and Italian Alps, is there a huge difference in terms of scenery? As this is once in a lifetime kind of trip, we would like it to be memorable too, without spending all our savings on it. Thanks for pointing out Dolomites. Will research this area and see if we can stick to Italian Alps instead of Switzerland/Austria. However, any advice in making this choice is welcome, as it is going to be a big decision. From our childhood, Switzerland has been known to be the epitome of scenic beauty and leaving it out would be a major decision!

Again, thank you @CL for tips on making the itinerary. Will work out day-time wise plan once we home onto something a little more concrete. As of now, these are just ideas.

Thank you @Judy.

One decision made - not renting a car :-) Your tips on luggage are most helpful. Did not consider cobblestone walks and hauling the luggage upstairs!! Thank you so much for pointing out. Yes, Paris was the only place chosen in France due to time constraints. Between most of France and most of Italy, we chose Italy and stuck to just one city in France. Traveling all the way and not visiting Paris did not sound like a good idea (considering that I don't see another vacation to Europe with family in the near or far future). We can extend the trip by a day or two, if we have to. Had thought that 18 days (ok 18 nights and 17 days) would be adequate and would be within budget. A little more stretch in budget might be better than missing out on something worth visiting.

As advised by you ad @CL, will try to plan the trip to the hour and see where it takes us. Thank you again.