Switzerland and Italy 2 weeks

Start with air. I can see some great prices on United from EWR to Milan in August, like $500 pp RT nonstops. It has good rail connections to Switzerland. You can look at apartments for longer stays, 2 hotel rooms for short stays.
Where do you want to go in Italy? For a short time (1 1/2 weeks) stick to the north like Florence and Venice.

Add every bit of time you can. As you do more trip planning, you will keep encountering places you wish you had time for. We all do. If you're going to spend the money to fly to Europe and deal with the first day (on which most if not all of you will be jetlagged and unable to do much sightseeing), better that it be for a 3-week trip rather than a 2-week trip!

However, I definitely would not add one week and try to tack on two more countries. I'd be much happier with just Switzerland and (mostly) Italy. At most, pick one limited area of France or Germany that holds interest for you. Italy alone has a tremendous amount of variety; many people spend a month or more in Europe and devote all of that time to Italy.

Be aware that Switzerland is expensive, substantially more so than the other countries you are contemplating. You can browse for hotels on a website like booking.com to get an idea of the price range. As a solo traveler, I cannot provide any guidance on family rooms, but I believe you need to look for rooms for 4 adults, based on the ages of your children. Others will for sure suggest that you consider apartments so you have more space. They come with the ability to do a bit of simple meal prep, which can save some money. A two-bedroom apartment may well be less expensive than two rooms in an upper-echelon hotel.

Switzerland aside (you'll be spending money there on high-mountain transportation as well as lodgings and meals), this need not be a horribly expensive trip as long as you're not looking for two Marriott-quality hotel rooms every night. If that is your expectation, it can get pricey in the most touristy locations (Venice being perhaps the prime example in Italy). You won't know until you shop around for lodging. Whatever website you use, look at all the pictures and read all the recent reviews for the places you are contemplating. You can learn a lot about probable expenses that way.

I don't think you need a travel agent to handle this.

Edited to add: Although most of us do pin down our flights early on, you need to be pretty sure how far north and south you want to travel before buying four airline tickets. It gets costly if your flights don't match your itinerary. If you get as far south as Rome, it will be more convenient to fly home from there. (Or you might prefer to start in Rome and work your way north.) If you want to see a bit of southern Germany, you might want to fly into Munich.

It is not too early at all to start pricing things out from your origin to possible European gateways. I like Google Flights, but there are other airline websites you can use. You can check a bunch of round trips to get an idea of what cities may be the cheapest gateways, then try choosing the "multi-city" option, which will allow you to fly into one city and out of another. This avoids the expenditure of time and money required to return to your starting point on the next-to-last day of your trip.

From my origin, comparatively inexpensive flights are sometimes available to and from Rome, Milan, Zurich and Munich. It may be completely different for you.

If you tell us your preferred origin airport(s), some folks here may have some ideas for you.

You don't need a travel agent; many of us do our own itinerary & on-line booking for flights & hotels.

I just checked Wengen (above Lauterbrunnen Valley floor) on booking.com and there were several hotel options with quad rooms with a sleeper sofa or you could book two double rooms together.

The most expensive area will be Switzerland for both hotels, train tickets & lifts, and food. Italy is much cheaper in comparison. So, plan your days wisely for Switzerland, and then spend more time in Italy. We did a similar trip for 14 days in 2014, and our total price for two people was $7500 (flew from West Coast); your budget is reasonable.

One problem you may face is that your kids are over 16 and considered adults in Switzerland and maybe elsewhere as well. Family rooms are not necessarily restricted by age, but might feel really small. Apartments will be more comfortable. .

One place I can recommend for you is the groundfloor apartment at Chalet Fontana in Mürren, above Lauterbrunnen. This is the best bargain I know in Switzerland. One bedroom has a double bed; the other has two twins. The other room is a kitchen-dining room. There is not a "living room" as we know it in the US, but the apartment is nevertheless comfortable.

If booking this trip I would start with that.

Switzerland is an easy country and I believe you can plan on your own. Although it is expensive, there are ways to save. Since you are in New Jersey, you should be able to find some very good airfare either from Newark, New York or Philadelphia. Keep in mind that July and August are the more expensive months to fly, so try to purchase soon. Depending on where you want to travel, I would fly round trip to Zurich or Geneva. If you fly from Newark or New York, you can fly direct - ideal on an international flight.
Airbnb is becoming more popular here and may be a good option since you are a family. Switzerland has excellent public transport, so even if your lodging is not right where you want to be, it's easy enough to get to where you want to visit. Purchase at least a 1/2 price card which covers most trains, busses, etc. Depending on where you want to go in Italy, consider flying with easy jet airlines rather than the train if the cost for four of you is high. As far as France, it may be a lot on this trip, but it depends. If you are in the Geneva/Lausanne/Montreux area, you can easily take the short boat ride there and spend the day. Lodging is not necessarily small. If you are in the city, it's likely smaller than if you are in the country. It's not common to have air conditioning. On the hot days, close the shutters during the day to keep the sun and heat out and open when the sun goes down. Try to pack light, especially if you are on the move. Layers are better as it gets cooler at the higher elevations.

Just to show you how random air fares have become: I am looking for dates in mid-May from New York to various European destinations. Nonstop flights from JFK to Zurich are about $350 (not a typo!). Nonstop flights to Geneva are about $1150, and even with a stopover, it's about $650.

Why does flying to Zurich cost one half or two-thirds the price of flying to Geneva? Who knows??

So, do check all prices. However, the advice above is also very important - figure out where you want to go before you book flights. Don't fly someplace just because the airfare's cheap, then waste a lot of time and money getting to where you want to go. For example, we often see people going to Italy book round trip to Milan (for a while, this was much cheaper than flying elsewhere in Italy), then have to use precious trip time getting to Rome or Venice, and back to Milan for their flight out.

For Swiss accommodations, be sure to e-mail them directly to ask about price and availability for rooms for 4 adults. I always do this everywhere, but I found that for Switzerland, the online booking tools didn't show all available rooms - even on the hotels' own website booking.

Unless you find a travel agent who really knows something about your destinations, they will just book things for you that you could have found and booked yourself, and they will charge you a fee for the privilege (very few places give commissions anymore).

If you need itinerary ideas, you can look at tours from Rick Steves as well as other companies. But be SURE to add more time. An organized tour can move much faster than you can on your own. I agree with two points made above - Switzerland is definitely more expensive than other countries on your list, for accommodations and particularly for food; and if you add more time, don't look to add more countries, but add more destinations in each country and more time in each destination.

Thank you all for your fantastic advice! Such a great forum! I've already researched the Chalet Fontana extensively, and that looks like a great option! Hotel Eiger also looks great, at about 3x the price! I think we will concentrate on Lucerne and Murren this go round. Two nights in Lucerne and 3-4 in Murren.

Some of you found very reasonable flights from Newark, NJ to Zurich in July or August. However, when I try to fly into Zurich and out from Rome the price increases dramatically. Any ideas on how to save on air, or is it worth it to return to Zurich to take advantage of better prices for family of four? I'm not afraid to travel a few hours if savings are worthwhile. However that is typically when I'm driving here in the US and it's really only a matter of drive time and gas, not a train or flight.

Thank you again everyone!

Try returning from Milan.

In the summer months, the fares are higher. Right now, there is a round trip ticket in July, Newark/Zurich direct for less than $700. These are some of the lowest fares I've seen during the summer in years, even though at this moment, Kayak is indicating to watch. Fares can change daily, so set up some price alerts and book right away. It's almost always cheaper to book a round trip ticket flying in and out of same airport. If you want to see Rome, easy jet to/from Geneva or Milan is less than $100.00 per person in July at this time. Book directly with the airlines you want to fly rather than a reseller. If you encounter a delay or cancellation, it is much easier dealing directly with the airline.

It's important to understand, though, that if you buy separate tickets for the transatlantic roundtrip and for one or more European flights on your day of arrival or day of departure, you have no protection if something goes wrong on the day's first flight. Therefore, I consider it to be worth some extra money to fly to (or within rail distance of) my first planned stop and to return to the US from my last planned stop. Each traveler gets to decide how much extra he's willing to pay for the security of not ending up with useless second-flight plane tickets in the event of first-flight delays.

If the savings from flying into and/or out of a bargain gateway in Europe look really substantial, that's fine, but understand that you need to allow a lot of time to make the unprotected connection. Otherwise, you may find yourself buying costly last-minute replacement tickets.

Indeed, if you are planning to visit Rome, I would not fly the same day as you would arrive or depart to/from your home country. Switzerland is a small country. You can easily fly into Zurich, travel to Lucerne, spend time there, then fly out of Geneva to Rome. Return and visit the next part of Swiss on your itinerary, then return to Zurich and fly home.

You can do this yourself. Start with Murren or Wengen for accomodations then figure out the others. Don't move too much. Also, every five or six days you will need a rest/laundry day. Since you have teens, get them involved. I made our 7 year old order a meal in the native language each trip. This might be something for the kids to enjoy. Also look at cell phone usage, rates and plans in europe.