How many cities in 27-29 nights?!

You know your own children best. I will point out, however that being away from home and routines that long will be stressful to them, even if it is happy stressful.

I would aim for 4 days in a location, a travel day, 4 days in a location, travel day. I’d also plan days just to chill.

Your biggest danger is trying to overdo/over schedule it. You will end up with cranky kids and cranky parents if the pace is too fast for the kids.

PS. I am assuming your children are homeschooled. Travel is a wonderful educational experience, but being gone that long during the school year can create issues without preplanning.

We took a 3 week trip when our teens were 11 and 14. We stopped in Boppard (3 nights), Rothenburg (2 nights), Salzburg (5 nights), Ljubljana (5 nights), Venice (3 nights) and Munich (3 nights). We had a car, and most travel times were under 4 hours, except Venice to Munich.

I think your plan of Paris, Amsterdam, Barcelona, Rome and London is literally all over the place, and you will spend a lot of time in transit. I would eliminate either London or Barcelona. You’ll take about a full day each time you move cities. Except Paris to Amsterdam. If you keep all of these cities, I would fly into London, then work your way to Rome. Fly home from Rome.

We learned quickly that museums and cathedrals all look the same after about 3 to kids. We did a lot more outdoor adventures (paragliding, sommerrodelbahns, exploring castles), and activities based on the kids’ interest vs. the parents.

With kids the less moving around the better. I would plan week London, week Amsterdam (or another smaller Netherlands or Belgium city), week Paris, week Rome (or another smaller Italy city like Bologna). Or consider doing not just cities so like London, a week in UK countryside, Paris, a week in France countryside. Staying longer in one place gives you more flexibility based on how the kids are doing, the weather, etc. to plan each day or a day trip out.

London, Amsterdam, and Paris can all be reached by the Eurostar train. I would figure out those 3 cities first, then get to Rome and leave from there.
With that many nights, you can easily do day trips, but, in our experience, day trips to cities, such as Florence, can be exhausting.
When we plan a longer trip with either multiple cities or countries, we get a starting and end point. Then we look at Rome2rio.com and start plugging in places to see the distance and modes of transportation between places.
Staying less than 3 nights can add to the exhaustion. Keep this in mind if trying to add too many places.

Definitely take a trip to Disney Paris, it’s fun! We went to Disney Tokyo and we didn’t even have our kids with us.

And remember, this might not be your only trip to Europe with your children. The first time we took our girls to Europe they were in HS. We started in Croatia, went to Prague, Vienna, Budapest, then back to Croatia (family visits). We ended up taking them 3 more times, the last one with their respective husbands.

PS, I agree with leaving Barcelona out, too far and Spain is a fabulous country to visit on its own for a month.

I have been to Europe 16 times but have never been to Barcelona(I have been to Seville, Granada, Toledo, Madrid, and Segovia, which should tell you my thoughts on Barcelona). I'm not sure Amsterdam is the best choice for children-they're too young for the Anne Frank House and probably have little interest in art museums. I would add more time in London-there are so many things to interest children there, as well as day trips. If you wanted another city in England, York has a lot to interest children, including an easy walk on top of the city wall and is an easy trip by train. Florence could easily be done as a day trip from Rome but you would have to carefully prioritize what you want to see in such a short amount of time. I don't know that the Uffizi would be on my list for children. There is an interesting science museum there so maybe one parent could take them there if the other parent is an art lover. Florence is a wonderful city for walking. Our daughter visited London at age 4 and Greece and Italy the summer after 6th grade.

I do hope your children are homeschooled. As great an educational opportunity as this is, making up a month's schoolwork would be a nightmare for your children and their teachers. It would be very inconsiderate to put this additional burden on teachers who are already overworked and underpaid in some, but not all, states. I speak from 27 years of experience as a high school science teacher.

Four weeks, four bases. Settle into a location and do day trips as well as city/local touring. Get apartments so you have a “home” and can have some non-restaurant meals especially when a long day makes everyone weary (and cranky!).

They don’t all have to be large cities, that is you could stay in Versailles instead of Paris, Haarlem instead of Amsterdam. As mentioned above, Barcelona and London are your outliers so drop one. Maybe London-Amsterdam-Paris-Rome. Take note of transfer times as unless you fly, you might want to take 2 days to go from Paris to Rome by train. You can use www.Rome2Rio.com to get travel time estimates but use the various countries rail websites to get actual schedules. Www.bahn.de is also an excellent planning site for rail.

It’s wonderful that your kids are involved in the planning. Once you have a solid itinerary, let them plan a day in each location.

I'm adding a link to the RS Family Tour 13-day itinerary. This is a good guide for you. It starts in London and ends in Florence. I would maybe skip Burgundy (although that castle-building thing sounds amazing). You have two more weeks to add stops.
So London, Paris, Alsace/Black Forest, Alps, Venice, Florence and Rome. This is a good mix of city and nature. It likely requires a combo of train and car. The best resource for train trip planning is The Man in Seat 61, https://www.seat61.com.
From London, you can visit the Harry Potter studio if your kids are into that.
Versailles? Ugh. How about Monet's garden and home in Giverny followed by the Orangerie to see the end product? That's an art experience kids can take in.
I love Amsterdam, but they are too young for Anne Frank House, so leave it for another trip.
You will NOT see everything. You won't even see everything you want to see. You're taking your kids, and you necessarily have to tailor the trip to their interests and tolerance. They will not remember everything (anything) they see. They will remember the fun they had, so make it fun for them (or leave them home with grandma and go on your own).
https://www.ricksteves.com/tours/europe/family-europe-london-florence

...have started calling this trip their “world adventure”...

It sounds like the kids are somewhat involved, but perhaps not as much as they should be. Not suggesting the inmates should run the asylum, but the more they are involve the better the trip will be for all.

For a trip that long, perhaps have each kid "plan" one thing in each locations. Not being critical, mind you, just offering food for thought.

I agree with Laurel's four weeks, four cities sentiment. I also agree with Barbara's choice of cities. So: London, Paris and Amsterdam via Eurostar, followed by plane to Rome. This minimizes travel time but gives them a taste of the big three, which I regard as London, Paris, and Rome. If you wanted to just take in the canal atmosphere and the cacophony of bicycles and then move on to a quieter town very nearby, you could try Leiden or Delft as a place to stay a very short train trip from Amsterdam.

While I don't have children that age, recently I was showing photos of my trips to Europe to some kids about the ages of yours, and all four cities grabbed their interest.

Have they been on a similar vacation with lots of walking? We did "stamina building" walks before having 7 nights in DC and we still heard complaints of sore feet and it was enough to make me put a stop to my (rather simple and short by comparison) trip I was planning for our family.
I will say that my 15 year old and I had such a lovely 11 nights in Paris. I know it's fun to see many places, but many of these large cities have enough to do to keep one busy for a month. And it was really nice not to have to pack and unpack multiple times. We did that last year in Italy and it was a great trip, completely different, but we both decided we really preferred our Paris trip. What about Paris, London, and Rome, at the most? And really make sure they have good shoes and socks!

I read that Rick Steves says the best place to take kids for a European vacation was to grandma and grandpa's on the way to the airport. and I don't like that, in a way, but in another way, I see his point.

wiebel,
We took our kids to France at ages 8 and 10. Part of the trip was to visit family, but 3 weeks of it was travel. We mixed up some kid- friendly things with typical sights. They still (at 45 and 47) remember most of the trip, and with fondness. Definitely pare down some of your locations. The London, Paris, Amsterdam, Rome combo is a good one for their ages. Barcelona is too much of an outlier. A week in each place is good. Every one of these cities has lots and lots to do so you will find many things to interest the little ones.

And don't ignore every museum and cathedral. Our two were highly impressed with Notre Dame and Versailles, as well as the suits of armor in the Invalides (army museum). (Aside...living in So Cal I wouldn't bother with Disneyland Paris, but that is me. I want a French experience, not a Disney one.) Don't underestimate your children's imaginations and interest in things you may feel aren't "child oriented" enough. In Beaune our ten year old daughter was fascinated by the altar polyptich at the Hospice, showing the Last Judgement. The beauty of the piece seemed to open up a door for her and she started looking at artworks with more interest from them on. It wasn't the religious theme, but the painting itself. Expose them to the cultural and artistic experiences. They may well surprise you with their enjoyment of them.

All four of these cities will easily fill your days, and all have some interesting day trips that are not a long slog. I won't go into details, but be assured that they are not just geared to adults. After all, the Italians and Dutch and English and French have families too. They take them to these cities (if they don't already live there) and find tons to entertain their kids. Just plan your transfers wisely and try to get lodgings akin to an apartment if possible. Ours loved the trip we took when they were 8 and 10, and have been back several times on their own, as well as with us. It will be a wonderful trip!

(P.S. I second the comments by cala about expecting teachers to accommodate the missed weeks of school by arranging and reviewing and grading their studies. The time it involves for a teacher when this happens is way more than people realize. As a parent, spouse, aunt and in-law of teachers, most parents haven't a clue about what all the special arrangements entail for the teacher (and usually on their own time). If you are their home-school teacher, then you, of course, will understand.)

What pbscd said: stamina-building trip. If your kids are not used to city touring, I'd say take them on a domestic trip (like DC or even Disney World) for Spring Break.

I really appreciate everyone's insight and suggestions. I am thinking that just the main 4 cities for a week each will really be the best approach for us. I am going to make sure the kids are really involved in the things we'll be seeing and will let them plan/choose activites as well and honestly I am a believer in living life WITH kids instead of doing things without them simply because its easier and I have already had a talk with them that there will be some things that they think are "boring" that we are simply going to do because mom and dad want to see this place/space and they both can recognize that and we are compromising by adding kid friendly things as well (Disney, etc.).. We take them to a lot of experiences that other people with kids the same age as ours say they would never do with young kids, but our kids always walk along, try new things and end up really having fun and talk about these experiences often. We are definetly going to do some more intensive "stamina" training but they are pretty good little walkers already and they'd both be 1.5 years older at the time of travel!

We are really fortunate to have the kids attend a school that really welcomes travel and allows for the kids to take time off school especially if they will be experiencing cultures and other experiences. Also there will be three statutory holiday days, and two non-instructional days in the time frame we have decided on. I have absolutely no expectation that the teachers provide work ahead and honestly missing 2 weeks in the first month of school and then missing a week around Thanksgiving is not something I am really concerned about because I believe that travelling is a great learning experience of both practical/life skills as well as historical/cultural learning. The kids will bring their own little cheap cameras and be given the chance to photograph/journal the most exicitng parts of the trip for them and share it with their class/peers when we get back and I think that is a really solid learning experience!

I concur with all the advice about four cities/four weeks. We did 16 nights in London/Paris with our three children ages almost 8, just-turned 11, and 14 1/2. This was in 2002, mind, but all three of them remember the trip fondly—and they all remember different things! We stayed in a hotel in London, and rented an apartment in Paris. The apartment was on Rue Suger, a block and a half from the Saint Michel metro, which was an ideally walkable location with the kids. The hotel in London was also right near a tube station, the South Kensington one I think; it was also ideal. We went to all the various museums and famous sites, and also did some things specifically aimed at the kids’ varying interests. Our now-30yo-son, the youngest, just stopped by our house, and I asked him what he remembers. Here’s what he said:
London:
1) Stonehenge. We took one of the chartered small-group tours that got us inside and among the stones, after the area closed to the public for the day. All three kids remember this as a major highlight, as do the adults! If you go, definitely get the tour that takes you into the stone circles. I don’t think it would have been nearly as memorable if we’d had to keep to the roped-off path that circles around the monoliths.
2) Brass rubbing at St. Martin in the Fields. The first thing out of my son’s mouth when I asked him what he remembers.
3) London Eye
4) The Crown Jewels
For reference, we went to the British Museum, the British Library, the Natural History museum, the National Portrait Gallery, the War Rooms, Greenwich, Hampton Court (including the maze—my older kids definitely enjoyed that). Westminster Abbey, and I went to the Florence Nightengale museum while my husband took the kids for a wander.
Paris:
1) Buying a French version of Chocolate Frosted Sugar Bombs at the grocery store, specifically for the prize, which was a little video game (!) and being shocked to discover that the game was… all in French :-)
2) A train ride into a village or something (We went to Giverny. )
3) The sandwiches at the corner stand (Ham and butter on baguette, at the stand by St. Michel. We bought lunch there at least 3 times)
4) Luxembourg Gardens: The carousel ride, specifically with trying to catch the brass rings on a little wand. And the puppet show—also in French but the stories are usually fairy tales so the plots are easy to follow. Ours was Little Red Riding Hood. The 14 yo skipped this, and the 11 yo was just on the verge of being too old, but the youngest was entranced. And I have to add, you haven’t lived until you’ve heard a roomful of French youngsters shrieking, “La loup! La loup!!! (The wolf! The wolf!!!) :-)
5) Seeing two French boys his age playing with Yu-Gi-Oh! Cards, which he was very much into at the time—and the cards were in French! Amazing!
6) A fancy place we went for dinner—because it smelled like smoke. Strongly of smoke.
7) Picking up chestnuts off the ground, taking them back to the apartment, and roasting them—and they were terrible. (My husband, the forager. Don’t ask.)
8) The Arc d’Triomphe and walking down the Champs d’Elysee. A very very long walk. Chocolates and pastries were had.
For reference, we also went to the Eiffel Tower, the D’Orsay, the Louvre, St. Chapelle, and lots of walking around the neighborhood. We just looked at Notre Dame from the outside but didn’t go in.
As you can see, the things he most remembers are the everyday things that were the same, yet different. And some of the specifically kid-friendly stuff I never would have thought up on my own. I’d completely forgotten about the brass rubbings, but for my son it was one of the highlights of the whole trip. I’d skip Disneyland Paris and spend the day in Luxembourg Gardens instead. And get an apartment if you can. Just shopping and cooking is part of the adventure, and a break from restaurants is welcome. I used versions of Paris with Kids and London with Kids to plan.

I also love including kids on adventures. I think being realistic and not packing too much into each day, having plenty of time to "bum around and eat ice cream" as my 8 year old says, are worth considering. Have fun!

Do your kids know/like the Madeleine books? She goes to Rome one springtime.

I am thinking that just the main 4 cities for a week each will really
be the best approach for us.

We took our three kids, who were a couple of years older than yours, to "just" London and Paris for a total of two weeks. We included a day at Disneyland Paris. Everyone loved it and compared it to the US parks we had visited. It's much bigger now and could be good for two days.

I have to begin by saying I don’t have children, but several nieces and nephews. Even though they were interested in many subjects at those young ages that many children aren’t, four weeks and four cities ought to fill the bill. I like that suggestion. Gives time for that ‘off’ day that all of us need. Hang out, read, just do regular stuff instead of go,go, go.

This is more about a possible substitution for Paris Disney. Certainly not as grand and a whole different set up but the Musee des Arts Forains and the Les Pavilons de Bercy was one of my best memories of Paris. A reservation is a must. It’s a bit tricky to get to, but we had the disadvantage of the main metro station in the area being closed due to the upcoming Olympics. Solved now most likely. We were unable to take the tour in English, but that ended up being half the fun as our guide was a show all on his own and his presentation in French was delightful. We thoroughly enjoyed that visit and we were in our early 70’s at the time. I would even go back given the opportunity.

Good luck planning and what an absolute amazing idea for your family.

Or do we stick with these 5 “main”cities and then tack on day trips if we find we have time??

This!

You will not be hassled every other day with packing, unpacking, checking out, checking in, racing to a train station, racing to an airport, etc. That to me is hell on earth.

Four cities, one week each makes sense. OR, two cities like London and Paris, plus 2 weeks in Italy, perhaps. With 5 or 6 days in Rome, 4 or 5 in Florence and 3 or 4 in Venice. You could take a day or two out of Rome and another from Florence, limit Venice to 3 and then you have a couple or 3 days for one of the following: Tuscan towns? the Dolomites? Lake Garda or Lake Como?

We spent a week in Paris (2010) and just scratched the surface. And we found it was not long enough to add in a day trip to either Versailles or Giverny, so those had to wait until 2023. With your kids, you will want to take those day trips to Disneyland and, probably Versailles.

In our week in London also in 2010, we also just scratched the surface and skipped major sights like the Tower (which your kids will love because of the Beefeaters and the Crown Jewels), National Gallery and Buckingham and Windsor Palaces. We did see other large sights, St Paul’s, Westminster Abbey, V&A, Hyde Park, as well as smaller ones like the Wallace Collection, Sir John Soane’s House, the Imperial War Museum and the Old Bailey, plus a day trip to Oxford with our friends and hosts who lived in Hampstead and who knew Oxford quite well, so we saw a lot that Oxford had to offer. Smaller city; fewer major attractions.

You ask about Florence. Florence is a good size city with many major sights. Our first trip there was in 2003. We spent three nights there and didn’t get enough of it. On that same trip, because we criss-crossed though Florence and stayed somewhat nearby in rural Tuscany, we later spent two more partial days in Florence and still didn’t get enough. When we returned to Italy in 2015, we spent another 3 or 4 nights in Florence, mostly to see places we missed 12 years earlier.

Is Florence a fantastic place to take your kids? Quite possibly. It is the birthplace of the Renaissance. Do your kids like art? Michelangelo, Donatello, Raphael and Leonardo may be familiar names to them. What do they know about the turtles’ namesakes? Might you read “The Agony and the Ecstacy” as a family read, aloud, to awaken their interest in art, history, adventure, and all things Michelangelo? You have lots of time to introduce that.

Since you are focused on BIG cities with major sights, and since you are folding in day trips, a week per city seems about right. I’d suggest that London, Paris, Rome, Amsterdam and Barcelona is too many. My inclination is to suggest just London (first stop - fewer language issues), Paris (ooh la la, the Eiffel Tower, Euro Disney and so much), and Italy as a place to settle into more and see more than just one city. Four different countries may be one too many for the kids to appreciate.

As for the kids, they will want - and deserve - park time and perhaps beach or swim time. They may get bored with churches and museums, so pick some kid friendly sights along the way. Train museums, Harry Potter, castles. Cycling a bit?