London to CDG

The Eurostar from London to Paris is around 3 hours, but then you'd have to add getting from Gare du Nord to CDG.

One problem if you want to take a taxi is the taxi queue at Gare du Nord is very small. Add to that everyone else getting off the train wants a taxi as well. It can take more than 45 minutes to get a taxi.

How long will you have in Paris? If it is less than 10 days, I don't suggest trying to take a quick trip to London. You'll burn up most of two days just traveling there and back.

I agree with DougMac that it's a time suck getting from London all the way to CDG. So let me throw out a couple of alternatives. Instead if returning to Paris, buy a multicity ticket into Paris and returning from London. Or start in London and return from Paris. That will eliminate one train trip (and a half day wasted on travel).

OR, if you must fly on a return ticket, continue on to London on your arrival day. That first day is usually mostly wasted due to jet lag anyway. Then spend your last days in Paris

The Eurostar from London to Paris is 2 hrs and 20 minutes (maybe 17 if we’re being exact). Not sure why everyone keeps saying it is three hours.

However, you do lose an hour since Paris is an hour ahead of London.

You wouldn’t need to bother with a taxi since the Eurostar arrives into Gare du Nord, and that is the station you need to get the RER out to the airport.

From our host's travel tips:

"Consider flying into one city and out of another. Since it rarely makes sense to spend time and money returning to your starting point, this strategy can be very efficient. For most "multicity" flights, the fare is figured simply by taking half of the round-trip cost for each of those ports, though you'll likely save money by using the same airline for each segment."

https://www.ricksteves.com/travel-tips/transportation/booking-flights

Are you considering a same-day round-trip? There's a lot of overhead, like waiting in line to buy Paris Metro tickets, not to mention IMMIGRATION before you board the Eurostar, in BOTH directions. That procedure could take more than the HOUR they ask for today, if there is a Brexit.

Thank you!!! I’ve looked into flying “open jaw,” as RS recommends ... I think it’s going to be too pricey. We will be in Paris 4-5 days and then over to London for 4 more. Hubby and I have been to both places already, so this trip is mostly for our daughter to experience them. I think CJean’s suggestion is a good one ... think I’ll look into that further!

remember that "open-jaw" is not three one-way legs. That would with most providers be very expensive, more than a round-trip plus a connector.

You want what most now call "multi-city" which is usually not far off the average of round trips to the two points, plus the connector.

I'm not saying that you are doing it wrong, just that there may be a better way to get the result you want.

One way on the Eurostar as the connector is pretty easy, and if you get your tickets well ahead can be quite a reasonable price.

When is the trip?

Check on open-jaw flying into London and out of Paris--it might be cheaper, as I understand there are high fees for flying OUT of London. Perhaps somebody else can verify that.

hey hey LV
when are you planning this trip and how many days? as others have stated, look at multi-city flights. don't know airport you're flying from in USA (USA - CDG eurostar to london - LHR - USA) or vice versa.
book the eurostar as early as possibly, maybe 4 months ahead, for the cheaper fares. by the time you add up costs of getting back to original arrival airport should be less than multi-city airline ticket. we do it all the time and it's so much easier and less stress.
we all a bit of nuttiness in us and always will. how old is your daughter and does she have things to see and do in paris. let her do some research, run it by you and decide then. so much to see and do in both paris and london, don't expect to see it all and cram everything. stop at cafe, relax, have a drink or bite to eat, people watch, enjoy the atmosphere.
ask more questions after you have looked into flights before booking and these folks will give you more options, the good bad and ugly and then you decide. just take it all in and the family will be happy. enjoy
aloha

To underline Nigel's point: You must search for your itinerary using a multi-destination search function. And remember that returning by Eurostar to France will be fairly costly. As to time, you will need to be at the Eurostar terminal long before scheduled departure; the line-up took nearly 90 minutes to board when I travelled two months ago. And then you have to RER to the airport. And then spend a couple of hours the next day to deal with Charles de Gaulle. Time is money and I'm betting that a multi-city ticket from London will save both.

Thank you all for the feedback!!! “Open-jaw” or “multi-city” ... is there a difference? (ETTBD called it “open jaw,” or so I thought, but airline websites seem to refer to it as “multi-city.”) At any rate, we’d be traveling through ATL and are close enough to make the drive, though we prefer flying in/out of our local airport.

If you end up flying roundtrip to/from CDG and you need to return to CDG, take the Eurostar to Gare du Nord and then do NOT take a taxi. You will sit in traffic and pay way too much money only to waste valuable time in the backseat of a taxi.

Instead, take the RER B train at Gare du Nord to CDG. So easy, so quick, so inexpensive even for 2. The ticket machines will accept your plastic too.

Open Jaw is an informal term created by Travel Agents to describe the appearance of lines on a map. Multi City is often the button to press before you enter your Flight Search on an airline website. It’s the third button or link, after One Way and Round Trip.