LHR to St. James Station

If you insist on the Heathrow Express or the Elizabeth line, you will pay a lot more, and then have to make a not very easy interchange either at Paddington in order to pay another fare to ride the District or Cycle to St. James Park.

If you take the Picadilly line Heathrow you will pay the base fare and while you have to interchange to that same District line, you will do it via a 30 foot walk across the platform at Hammersmith. With luggage this cannot be easier.

Thank you! That's just the help I needed. In case it matters, this will be on Sept. 14 around 9:00am.

Anything along the bottom of the Circle / District Line will be easiest (and often quickest in practice) using the Piccadilly & District as above under normal circumstances, apart maybe from Westminster & Embankment and that would be marginal.

The TfL journey planner is better than any other app or website simply because it is based on live running data.

The default setting is the fastest route which will always be Heathrow Express.

But on the results page you can 'edit preferences' to exclude National Rail (Heathrow Express in this case) and/or Elizabeth Line- which forces it to give you the tube route.

Download the Citymapper app. I find it better than the TFL journey planner.

The distance to change trins at Hammersmith is more like 15 feet. :)

You can also change at Baron's Court the stop after Hammersmith. The platform situation is the same as Hammersmith.

Frank, every time I have done that interchange it has been on the way from Heathrow after the overnight flight, and really unable to correctly eyeball the distance. All I know is it is really short and I think I saw it called “30 feet” on here over the years!