Cheapest Day to Buy Flights from San Francisco to London
San Francisco to London is 8,616 km (5,354 mi) great-circle — commonly 8–12 h nonstop or with 1 stop. Fares typically bottom out 3–12 weeks before departure; the calendar below shows the cheapest price for every day of the next 12 months.
Check live prices on Aviasales ↗Low Fare Calendar — San Francisco to London
When to book vs. when to fly — San Francisco → London
Live data from recent Aviasales searches for SFO → LHR, plus a booking rule of thumb.
Lowest indicative per-adult round-trip fares seen in Aviasales searches — confirmed live on the booking site before payment.
See the cheapest month’s fares ↗Search any date — San Francisco → London
Flight options — San Francisco → London
Recently-seen round-trip fares — click any flight for details, alternatives and booking.
Never miss a price drop on this route
Get a notification when fare forecasts reach historical lows for San Francisco to London.
Only fare-drop alerts for this route. Unsubscribe anytime — see our Privacy Policy.
FAQ — SFO → LHR
How much is a flight from San Francisco to London?
Prices vary by season and departure day. The Low Fare Calendar on this page shows the cheapest fare for every day of the coming year between San Francisco (SFO) and London (LHR).
Which airlines fly from San Francisco to London?
The San Francisco → London route covers about 8,616 km and commonly 8–12 h nonstop or with 1 stop. Multiple carriers operate it — search FlyTiming to compare every airline and agency serving SFO → LHR in one search.
What is the cheapest day to fly from San Francisco to London?
It varies by month. The price card on this page highlights the cheapest month and the historically cheapest day of the week to fly this route — the Low Fare Calendar below marks low-fare days in green.
When is the best time to book flights from San Francisco to London?
As a rule of thumb, fares on international routes are usually lowest roughly 3–12 weeks before departure — and northern-summer peak (June–August) usually means the highest fares — book early or aim for the shoulder months. The calendar below is the fastest way to spot the cheapest months for San Francisco → London.