London to San Francisco LCY, LGW, LHR, LTN, STN → SFO
London City Airport (LCY), London Gatwick Airport (LGW), London Heathrow Airport (LHR), London Luton Airport (LTN), Stansted Airport (STN) → San Francisco International Airport (SFO)
The cheapest return found recently is $707 with Finnair, 28 Dec – 9 Jan 2027, found yesterday.
Return
The cheapest return fare on each of 3 departure dates is usually $574 to $641.
Cheapest return found recently
$707
28 Dec – 9 Jan 2027 · Finnair
London Heathrow Airport (LHR) → San Francisco International Airport (SFO)
Leaves 11:00 a.m. · Return leaves 1:18 p.m. · 33 h 26 min of travel, both ways together
out 1 stop, back 1 stop
found yesterday
Cheapest nonstop return
None seen yet.
Found recently, and the cheapest we hold
$707 28 Dec – 9 Jan 2027found yesterdaySee prices for these dates
$574 29 Oct – 12 Novfound 5 days agoSee prices for these dates
What have prices looked like?
Over 25 days, 24 Sept to 18 Oct, the cheapest return we saw each day was $484 to $612.
At $707, the cheapest return found recently is above that range.
25 days is a short history, so treat this range as an early guide.
Those were the prices on those days, not today's.
Is this a good return price?
Compared with the cheapest return fare on each of 3 departure dates from 29 Oct to 28 Dec, found by travelers' searches in the last 7 days (economy, the price the seller showed on Aviasales). The usual range is the middle half of those prices.
Could nearby dates be cheaper?
We hold no other 12-night return fares leaving within 3 days of 28 Dec to compare.
Every date we hold
11 fares on 3 departure dates
See the chart as a table
| Dates | From | Airline | Airports | Stops | Found | |
|---|---|---|---|---|---|---|
| 29 Oct – 12 Nov | $574 | Alaska Airlines | London Heathrow Airport (LHR) → San Francisco International Airport (SFO) | out 1 stop, back 1 stop | found 5 days ago | See prices for these dates |
| 20 Nov – 24 Nov | $574 | Alaska Airlines | London Heathrow Airport (LHR) → San Francisco International Airport (SFO) | out 1 stop, back 1 stop | found 5 days ago | See prices for these dates |
| 28 Dec – 9 Jan 2027 | $707 | Finnair | London Heathrow Airport (LHR) → San Francisco International Airport (SFO) | out 1 stop, back 1 stop | found yesterday | See prices for these dates |
Which month looks cheapest?
October 2026 is the cheapest month — from $574.
Airlines on the cheapest dates: Alaska Airlines, Finnair.
Premium cabin fares from London to San Francisco
We hold no premium economy, business or first-class fares for this route: we collect them for the busiest routes, and this one is not among them yet.
Today's prices for 28 Dec – 9 Jan 2027 in another cabin: Premium economy · Business · First
How far ahead were prices cheapest for London to San Francisco?
Return
Fares 7 to 13 days before departure were typically 48% lower than 0 to 6 days before departure.
From the cheapest return each day between 24 Sept and 18 Oct (25 days), grouped by how many days ahead the flight left; one adult in economy.
Each range covers different departure dates, so this compares typical fares, not the same trip priced twice.
Prices reflect recent searches — current fares may differ.
See these ranges as a table
| Booked ahead by | Typical fare | Cheapest day | Above the cheapest | Days of prices |
|---|---|---|---|---|
| 0–6 days | $1,000 | $531 | +91% | 11 |
| 7–13 days | $524 | $498 | Cheapest seen | 13 |
| 14–29 days | $574 | $490 | +10% | 11 |
| 30–59 days | $590 | $495 | +13% | 17 |
| 60–89 days | $527 | $527 | +1% | 8 |
| 90–179 days | $575 | $484 | +10% | 22 |
| 180+ days | $675 | $573 | +29% | 11 |
Live price for these dates
The cheapest return found recently is for 28 Dec – 9 Jan 2027. A live search on this page shows what those dates cost now, for one adult in economy.
Prices are what travelers' searches on Aviasales found in the last 7 days, in US dollars: the price the seller showed on Aviasales; bags may cost extra. Fares change, so check today's price before you book. How our prices work