Gare St. Lazare to Gard Nord

If you mean the train station Gare du Nord, then it will take about ten minutes: http://g.co/maps/5rgmy

Ten minutes, maybe a bit less.

Thanks so much sure helps with logistics on getting from Paris to London.

Shelley, The travel time via Taxi from Gare St. Lazare to Gare du Nord will likely depend to some extent on the time-of-day and traffic conditions at the time. You could also travel via Metro / RER on that route, with an estimated travel time of about 25 minutes. I'm also a "senior" and that's the method I'd prefer (although some walking would be involved - the Metro arrives at Chatelet and it's a short walk through the passageways to Chatelet - Les Halles, where the RER departs from). Happy travels!

Your question was asked and answered, but maybe you asked the wrong question. The actual movement via taxi can't take more than fifteen minutes, even at high noon with a thousand delivery trucks stopped in the right lanes. Now, if you add in the time it takes you to get to the taxi rank from the door of St Lazare (assuming you go out the correct door the first time), load you junk, make the ride, Unload your junk, hike into Nord, find the platform, etc. You could burn up closer to an hour. Then you tossed in a kicker - - you're going to London. Check-in for the Eurostar has to be done and over with a half hour prior to scheduled departure. Don't try to cut it too close, especially if you've already paid for those tickets. I can't agree with Ken's idea of taking a route through Chatelet. That place is a mess if you're not used to it. It call itself the largest underground station in the world - - maybe, maybe not. But it can be a zoo. My metro/rer idea would be to tunnel-hike from G. St Lazare to Haussmann Saint-Lazare, hop the rer E to Magenta (no stops) then tunnel-hike again over to Nord. The time on the train is real close to the time spent in a taxi, the walking distance is maybe a bit more (but not much). A couple of metro tickets will be less than five bucks; a taxi maybe fifteen.

I'm with Ed. The RATP site says that you should allow 7 minutes to walk from Gare St-Lazare to the Haussmann - St-Lazare RER station and 3 minutes to walk from the Magenta RER station to Gare du Nord. The ride on the RER E from Haussmann - St-Lazare to Magenta takes 3 minutes.