The cheapest order to fly London, Paris and Barcelona from San Francisco
There are 6 ways to fly these cities. They do not cost the same. The cheapest works out at about $822 a person and the most expensive at $957, a difference of $135 for visiting exactly the same places.
Fly them in this order
San Francisco → London → Barcelona → Paris → San Francisco
About $822 per person in flights, based on fares recently seen on these routes.
Every order, priced
- San Francisco → London → Barcelona → Paris → San Francisco$822cheapest order
- San Francisco → Paris → Barcelona → London → San Francisco$831$9 more per person
- San Francisco → London → Paris → Barcelona → San Francisco$839$17 more per person
- San Francisco → Paris → London → Barcelona → San Francisco$839$17 more per person
- San Francisco → Barcelona → London → Paris → San Francisco$940$118 more per person
- San Francisco → Barcelona → Paris → London → San Francisco$957$135 more per person
Why London first
- San Francisco to London$299
- London to Barcelona$29
- Barcelona to Paris$28
- Paris to San Francisco$466
- Out of San Francisco, London is the cheapest first stop at about $299. Barcelona would be $417.
- Paris to San Francisco is 57% of what the cheapest order spends on flights, so it is the leg to watch.
Between the cities
- London to Barcelona: about 1,140 km (710 miles) as the crow flies. No train or bus we would suggest instead of flying.
- Barcelona to Paris: about 830 km (520 miles) as the crow flies. Also by ground: TGV, about 6h 40m, usually $50 to $150.
Entry rules on a US passport
- US passport: the UK requires an Electronic Travel Authorisation (ETA) for visa-free visitors, including short visits and landside transit. Apply via the UK ETA app before travel. Official source
- US passport: visa-free in the Schengen area for 90 days in any 180. The Entry/Exit System registers biometrics at the border, and the ETIAS pre-travel authorisation may now be required; check the official site. Official source
Rules change; check the official source for your passport and dates before you book.
How much the order matters here
Getting the order right is worth $135 a person on this trip, 16% of what the cheapest way round costs. Of the 72 trips we price in full, that is number 53 for how much the order matters, one of the smaller gaps: on this trip your dates are likely to matter more than the order.
The same cities from other airports
The cheapest order depends on where you start. From San Francisco it starts in London.
- From New Yorkstart in Paris, about $458 a person, $241 less than the dearest order
- From Los Angelesstart in Paris, about $752 a person, $182 less than the dearest order
- From Chicagostart in Barcelona, about $822 a person, $200 less than the dearest order
- From Atlantastart in London, about $878 a person, $200 less than the dearest order
What these numbers are
Cached one-way fares, 12 of 12 legs priced from real observations, put together on October 29, 2026, from fares departing October 31, 2026 onwards. Right for comparing one order with another, not a quote for your dates.
A plan prices your own dates and weighs hours as well as fares, so it can pick a different order from this page.
Put dates on it
Same cities on real dates, plus what one search cannot show: layovers long enough to count as a free city, two tickets that beat one, and cheaper days either side. No account and no card.
One press starts it on January 2, 2027 to January 16, 2027, 14 days, for 2 travelers. Our dates, not yours, and about two minutes.
Plan London, Paris and Barcelona from San Francisco nowOpen the form instead and pick your own datesSigned out, 3 plans a day per address, priced from cached fares and the free sources, so some legs may be estimates and the plan says which. Signed in, legs are checked live, with 2 free trips you can change afterwards.