Total travel time by tube from Pancras to Heathrow

Plan on 15 minutes walk plus or minus from the train (quite a long train) to the Piccadilly Platform if you already have your Underground ticket or Oyster Card loaded with sufficient credit. The Underground takes about 1 hour, a bit less or a bit more depending which terminal you are going to. It is a frequent service. You'll need to know the terminal. Figure 15 minutes plus or minus to the frosted doors depending on the terminal. So that's 90 minutes plus or minus. Expect your wife to take 60-90 minutes, on average, from landing to the frosted doors. You might be able to take a train arriving a bit later and still be waiting by the frosted doors for her to come out. Remember a couple of things - the strictly enforced minimum 30 minute Eurostar check-in; and to be careful of Engineering Works on the Underground if you are making the journey on a weekend or a Bank Holiday. Happy planning...

Nigel, Thanks very much for the excellent answer! I really appreciate your help! I've scanned Eurostar times from Paris and Brussels, and it looks like the most appropriate trains from either point arrive around 2 hours before I'd want to be at Heathrow, so I'm good to go! I just have one detail question. Are you saying the 15 minute walk to the Picadilly platform is from the Eurostar platform at St. Pancras to the Picadilly tube station platform? I.e., I don't get the tube right IN St. Pancras station itself, I have to walk outside and down the street, so to speak, about 15 minutes? That's no problem; I just want to make sure I understand you. And I understand the proviso about already having my fare card paid ahead of time. If I don't have that, I'd have to add a few minutes to take care of that. I've ridden subways, metros, tubes, etc., all over the world, so I can handle that part. Again, thanks for such a precise and detailed reply! Long story short, 120 minutes from Eurostar pulling in to facing the frosted doors sounds like it'll work exactly right! Thx. Tom

From Paris or Brussels you have the alternative option of flying to LHR. Maybe a bit more travel time at the front end but less at the back. There isn't that much difference in the cost.

Just make sure you have a backup plan in case your train is delayed or her flight is delayed. I've had two long delays on Eurostar over the years (one was 3 hours and one was 6 hours). That is definitely not the norm, but the trains don't always run like clock-work.

The closest Underground station to St Pancras International is King's Cross/St Pancras. As you can tell by the name, it's also close to the King's Cross national rail station. The station is served by the Piccadilly Line and the Northern Line.

Tom, you asked about the 15 minutes from train to tube train. It sounds like a lot, but let me explain. I don't know which carriage you will be in, and the train is, as I said, quite long. St Pancras is a dead end station so everybody has to walk to the nearly front of the train, then downstairs, then through the station, then go down further into the Underground station which is not down the road but under the road. Then down to the platform using escalators and stairs, then wait the few minutes for the Underground train. Now I don't know how fast you move, so I'm saying 15 minutes plus or minus. Little things add up. Maybe you walk down escalators with your luggage. Maybe you'll get stuck behind people. Dunno. I bet when you time it, it won't be far off 15.

Thanks again, everyone. Nigel, your explanation about the Pancras dead end platform and long trains reminds me of a hilarious (but off-topic) episode I heard about when I was a daily commuter in Chicago. Their platforms are dead end also, with only one small door into the station itself at the front end of each train. So of course impatient commuters all want to sit in the first few cars of a 10-car train, so they can hop off the train the instant it comes to a stop and don't waste too much time in the huge jam up getting off the platform into the station. So the front few cars are always crammed with passengers and standees, while the back half of any train always has plenty of seats. Well, one conductor collecting tickets said he was pushing himself politely through the crush of passengers in the front few cars one morning, including enough standing passengers that it was hard for him to move at all, when he encountered an angry, befurred dowager standing in the aisle complaining loudly about not being able to sit down, because it was so crowded. He explained to her patiently why people wanted to sit near the front of the train and that there were often many seats five or six cars back. He said she replied, "Well then, why don't they put more cars on the front!" When he told this story later, he said "I couldn't think of anything to say in response to that, so I just walked away..."

To elaborate on Tim's mention of the Northern Line as well as the Piccadilly, it is actually even more than that. Kings Cross St Pancras is a true hub of the Underground and trains. Within the Underground station are: Northern Line Bank Branch (black) Victoria Line (blue) Piccadilly Line (dark blue) Circle Line (yellow) Hammersmith and City Line (pink) Metropolitan Line (purple) Linked from that Underground station is the station for the Thameslink trains of First Capital Connect north to Luton Airport and Bedford; south through the City to East Croydon, Sutton, Gatwick Airport and Brighton. From St Pancras station in addition to the Eurostar trains to Paris and Brussels there are East Midlands Trains to Wellingborough, Kettering, Leicester, Derby, Nottingham and north to Sheffield and York Southeastern Javelin bullet trains to Ashford, Dover and Canterbury From Kings Cross station across a small street, directly linked by tunnel, are East Coast trains which provide 125 mph trains up the East Coast Main Line to York and Edinburgh, Durham and Newcastle First Hull Trains to - Hull Grand Central Trains to York and Sunderland
First Capital Connect trains to Cambridge and East Anglia to Peterboough; Ely and King's Lynn Kings Cross has a pretty nice food court upstairs - including a Benito's Hat for a quick burrito fix, and the photo op at Platform 9 and three quarters - a little distance away from the actual platform 9. St Pancras has quite a few food outlets, across the board, including what they advertise as the longest Champagne bar in the world. So, its all going on down at the depot.

Nigel is right, of course, about more Underground lines than I listed. Since I'm very familiar with the Underground map, I'm embarrassed that I missed those lines.

http://parkinginstevenage.files.wordpress.com/2009/12/king-cross-upgrade-map1.gif There are two major entrances to Kings Cross St. Pancras tube station and as it notes there are two entrances to the tube--one is at the very front and the other is closer to the back near the Southeastern High Speed trains. Also the Eurostar website advises that there are additional document checks that may be in effect on the Brussels line which they say add in 30 minutes for. I would also seriously consider another option as well and that's to go out of Paddington by either the tube--Circle Line or Hammersmith and City and then take either the Heathrow Express or Heathrow Connect to Heathrow. The Express takes 15 minutes to Heathrow Central and about 20 minutes to Terminal 5.