20 day trip to Europe: Germany, Italy and Spain

You have 17 effective day in Europe and plan to spend perhaps 4 in Germany, leaving you 13 days. 13 days considering you are going to Madrid at the end of the trip. I would plan for at least 5 days in Madrid. Three days to see that city with day trips to Toledo and Segovia. That leaves you with 8 days, not counting travel. Going to Italy from Munich will take some time, especially if you go to Rome. You could take the overnight train to Rome, that would save time, but I don't think seeing the three Italian gem cities in 8 days is a good thing.

If you decided to spend those 8 days in Italy, plan to two nights in Venice, three in Florence and three in Rome. An alternate is to visit something closer to Germany, like Prague and/or Vienna. If you still want to do Italy, consider skipping Rome (for another trip) and more time in Northern Italy.

I know how tempting is to crowd everything in a short stay, and I feel I'm doing that... I want to be realistic and yet visit as many cities as possible.

I agree that you are right to be concerned about trying to do too much. It looks to me like you are.

Without the traveling days we have 17 effective days to enjoy our vacation..

Only if you expect to be able to magically transport yourself between locations.

You are not taking into account the time it takes to pick yourselves up from one place and move to the next. You have listed a minimum of 7 locations you want to include, and almost all of them are at least somewhat far from each other...that's going to eat up a day in transit every time you move (at best, you might be able to connect some of these places in half a day - most will take nearly a whole day to connect). So you are going to end up with 1 to 1.5 days in many of these places. One day in Rome? In Barcelona?

You left out a couple important details: you say that you (and your brother) "have traveled to Europe a few times and I'm unstoppable" but how about your parents? Remember, you may be happy to wake up, stuff your toothbrush in your backpack, and charge off to the train, but your parents may prefer (or require) a different pace. And you say "We bought a round trip to Madrid" - who did? Just you and your brother, or your parents, too? Given your study in Germany, and your interest in visiting and showing your family Germany, Spain and Italy, a round-trip ticket to/from Madrid doesn't make sense to me.

Honestly, if it were me, and I had 17 days to spend showing my family around Europe, I would pick two countries, not three. It sounds like you have already effectively "picked" two - Spain (you have flights in/out of Madrid) and Germany (you're studying there) - and are trying to find some way to squeeze in Italy, too.

It would have been much more efficient to fly open jaw into Germany and out of Spain (or Italy) to avoid backtracking. Consider if you can change your flights to a more logical routing (even if you have to pay more - you may end up saving money, or "buying" a couple more days by doing that, or both - once you figure in all the actual costs).

If you are stuck with flights you just can not change, then I'd make the best of it by: skip Italy, save that for another trip. There's plenty to see in Germany and Spain.

Hope some of that is helpful

I think if you want to go to Italy you'll need to fly from there to Spain. I love Barcelona, but I'd leave it for another trip since you're tied to a Madrid departure and there are, indeed, some wonderful side-trips to take from Madrid. Before deciding how many days to set aside for Madrid, give serious consideration to how much art museum time you will want there. You're going to be cutting Italy to the bone. If you do not intend to spend a lot of time at the Prado, Reina Sofia and Thyssen, I think you don't need five days in Madrid if you're only taking two day-trips--not at the expense of Venice, Florence and Rome.

Take a look at Skyscanner for flight options from Italy to Madrid to help you structure the Italian leg of your trip. You may find it's much easier or cheaper to get to Madrid from Rome than from Venice or Florence, for example. (Or not; I haven't checked.)

Don't forget that you may well have very hot weather throughout your entire trip. That can make it a bit more difficult to keep going like the Energizer bunny day after day.

Looking at a reasonable minimum...

Meet in Munich/Berlin (3 nights)
Fly to Venice (3 nights)
Train to Florence (2 nights)
Train to Rome (3 nights)
Fly to Barcelona (3 nights)
Train to Madrid (3 nights)

Thank you for your advice, guys. We discussed our priorities as a family and decided that is better if we exclude Germany and travel to Italy and Spain. My brother and I will meet our parents in Italy to start our vacation there. Thanks again!

That would give you 3 nights to re allocate ...

Meet in Venice (3 nights)
Train to Florence (3 nights)
Train to Rome (4 nights)
Fly to Barcelona (3 or 4 nights)
Train to Madrid (3 or 4 nights)