Flights Bangkok to San Francisco (BKK-SFO): Airlines, THB Fares

Bangkok to San Francisco connects Thailand with the San Francisco Bay Area, home to a substantial and well-established Thai community. The route carries people visiting family, students and academics, technology-sector professionals, and travellers using San Francisco as their entry point to Northern California and the wider US West.

There is no nonstop service; block times near 17.8 hours reflect a single connection through the operating carrier’s Asian hub. With around 10 flights a week, the corridor is dependable, and demand peaks around the long school holidays and the year-end.

Corridor profile

The BKK–SFO corridor runs about 10 departures a week across 4 carriers, with an average block time of 17.8 hours, and the lowest fare the feed returned for this route is ฿25,285. The frequency figure counts every carrier on the route combined, not any single airline.

Our own demand score. This corridor scores 7/10. That is an editorial ranking we use to prioritise how deeply we cover a route — it is not a passenger count and not a price index. A high score means a corridor people search and where options exist, which usually means price competition. A low score does not mean a bad route; it means fewer options, and where options are few, flexibility gets expensive.

What frequency tells you when plans break. 10 weekly departures is ~1.4 departures a day — the next departure is usually same-day or next-day. That is why frequency matters more than price for anyone with a fixed commitment at the other end. A thin corridor deserves a buffer day before anything that cannot move, not because the airline is poor but because there is no spare inventory to shift you onto.

Airlines & baggage

Baseline baggage on BKK–SFO runs 30 kg across the 4 of 4 carriers on the route for which we hold a row. These are carrier reference baselines, not entitlements attached to every ticket: cabin class, fare brand and frequent-flyer status all change the weight you actually get.

Bags through-check only on one ticket. The carriers we hold rows for on this corridor are not all in the same alliance. A bag runs through to your final destination only when every sector sits on one ticket, or an interline agreement exists between the operators. Self-connect on two separate tickets to shave the total and you collect the bag, clear the transit country’s immigration, and check in again — and the time you must allow is far longer than a booking screen implies.

Airlines on this route

4 carriers operate BKK–SFO — all full-service. Alliances present on the route: Oneworld, SkyTeam, Star Alliance. Multiple carriers only affect price when both sides are actually selling in the same window. We hold 4 monthly lows spanning a 43% range.

Four carriers serve BKK-SFO, all full-service and all routing through a hub: EVA Air via Taipei, Cathay Pacific via Hong Kong, Korean Air via Seoul and Thai Airways. On a journey approaching eighteen hours, the connecting airport, the layover length and the checked baggage allowance matter as much as the headline fare. Comparing two or three carriers on the same dates is usually worth the effort, as schedules and prices differ between the hubs.

Carrier count is not year-round competition. Some operators fly this corridor seasonally or on selected weekdays. In a week where only one is genuinely selling, the fare behaves like a monopoly fare. The fastest check is how many carriers actually quote your dates, not how many have ever served the route.

Monthly market-low pattern (THB)

Across the 4 months in our cache the lowest recorded fares run from ฿12,540 (Dec 2026) to ฿17,870 (Aug 2026), a 43% spread. Each value is a single snapshot, not that month’s average. This corridor scores 7/10 on our own catalogue demand ranking.

The price is attached to a date. Our most recent low is tied to a 2026-08-13 departure. Fares on international corridors move with the day of week and the holiday calendar more than most travellers expect, and shifting the date by one or two days usually does more for the price than switching airline. If your dates are fixed, read this number as a theoretical floor rather than something you will be offered.

A missing month is not a missing flight. The table shows only months where a capture succeeded. A month that is absent has no recorded value from the latest pass — usually because the schedule is not yet on sale, or because that capture returned nothing. It is not a signal that the route has closed. Check live pricing for the month you care about.

Fare trends

Between 2026-W20 and 2026-W31 we captured the BKK–SFO low 8 times, ranging ฿25,285 to ฿38,158 — a 51% spread. The cheapest reading fell in week 2026-W31, and from first capture to last the low moved down 11%.

BKK-SFO is a long, premium-leaning route where booking ahead pays. The year-end holidays and the mid-year break are the busiest and dearest — eight to fourteen weeks of lead time is sensible for those windows. Outside the peaks, a six-to-ten-week window often finds a workable economy fare in THB, with the hub carriers competing on connecting itineraries. Flexible dates and an open mind on the transit hub both help.

This is the lowest fare our feed returned for BKK–SFO, not a quoted price. It is the minimum of the record we hold for this one corridor — not the lowest value in our fare cache, not an average, not a live quote, and not a promise that a seat still exists at that number. An unusually low reading almost always traces to one carrier’s limited promotional inventory, which is gone before you reach checkout. Treat it as a reference line for how low this corridor can go, then check live pricing before deciding.

Seasonality & best time to book

Our catalogue lists 4 carriers on this city pair. BKK–SFO peaks when the Thai community abroad travels at the same time — Songkran, New Year and the long school break. The side effect most people miss is that the return leg often prices higher than the outbound in the same week, because demand stacks in both directions at once.

Bangkok–San Francisco fares move with demand. The cheapest windows fall outside school holidays, Songkran and New Year; book 4–8 weeks ahead for normal dates. As a migrant-worker corridor, demand rises around contract turnover and long holidays — book early.

What our data actually shows. Of the 4 months we captured, the cheapest reading was Dec 2026 at ฿12,540 and the dearest Aug 2026 at ฿17,870. These are observations, not a forecast for next year: a month that read cheap in one pass may not in the next. Use it as a starting point for comparison, not a fixed calendar.

The booking window matters more than the booking day. On a 17.8-hour corridor the fare tracks how many seats remain in each fare bucket, not which weekday you click buy. The folklore about a magic booking day has no support in the series we capture. What does show up is widening your travel dates by a day or two.

About San Francisco

San Francisco (SFO) sits in USA. The flight from Bangkok runs about 17.8 hours. The trend figures rest on 8 weekly captures since week 2026-W20. We hold 4 monthly lows spanning a 43% range. This corridor scores 7/10 on our own catalogue demand ranking.

San Francisco is the urban heart of a wider Bay Area that includes Oakland, San Jose and Silicon Valley — a region with deep Thai community roots and a strong draw for students and professionals. The city itself is compact and walkable, set on hills above the bay, with a famous fog, distinct neighbourhoods and a long food culture. For Thai travellers, San Francisco works as a family destination, a study or work base, and a gateway to Northern California.

Local time at the destination. San Francisco runs on America/Los_Angeles, 15h behind Bangkok. This zone observes seasonal clock changes, so the gap is not constant across the year — check the offset for your actual travel dates. The offset matters most on overnight flights, because the times on a ticket are local at each end rather than an elapsed duration. Misreading the arrival time is a common way to book a transfer or a hotel night on the wrong date.

Passenger rights on BKK–SFO

Our catalogue lists 4 carriers on this city pair. Departures from Thailand fall under Thailand CAAT; the return from San Francisco falls under US DOT — Aviation Consumer Protection. The two regimes are not the same, and what you are owed changes with the direction of travel and the nationality of the operating carrier — never with the fare you paid.

There is no US EU261. US DOT — Aviation Consumer Protection governs refunds when a flight is cancelled or significantly changed, tarmac-delay rules, and compensation for involuntary denied boarding — but there is no European-style cash schedule for delay or cancellation. Expecting a delay payout on a US itinerary is one of the most common misreadings of the rules. Departures from Thailand remain with Thailand CAAT.

Baggage and delay are governed by different instruments. If a bag is lost or arrives late on an international journey, the basis of claim is the Montreal Convention 1999, which applies where both the origin and destination states are parties. Its ceilings are denominated in SDR and revised periodically, so only the current figure is citable. The practical consequence is that the two claims are independent: having no delay-compensation right does not remove a baggage claim, and the report should be filed at the baggage desk before you leave the airport.

FAQ

Which airlines fly Bangkok to San Francisco?

The BKK-SFO route is operated by EVA Air, Cathay Pacific, Korean Air and Thai Airways. Compare baggage, alliances and fares in the table above.

How long and how often is the BKK-SFO flight?

Block time is ~17.8h, with ~10 flights per week across all carriers.

When is BKK-SFO cheapest to book?

The lowest fare our feed returned for this route is ~฿15,639. Book 4–8 weeks ahead; avoid Songkran, school holidays and peak season to save 15–30%.

What exactly is the lowest fare shown on this page?

It is the cheapest fare our cache has recorded on BKK–SFO, captured one snapshot at a time. It is not an average, not a live quote and not a guarantee that a seat still exists at that price. Use it as a reference floor, then check live pricing.

What is the difference between a direct and a nonstop flight?

Direct means the flight number does not change, but the aircraft may still land en route. Nonstop means no intermediate landing at all. If the clock matters, filter on nonstop, not direct.

Does the US have EU261-style delay compensation?

No. US DOT rules cover refunds for cancellations and significant changes, tarmac-delay obligations and compensation for involuntary denied boarding, but there is no cash schedule for delay.

Will my bag be through-checked if I book two separate tickets?

No. Through-checking happens only when every sector is on one ticket or an interline agreement exists. On separate tickets you reclaim the bag, clear the transit country’s immigration and check in again — and a missed connection is a new ticket at your cost.

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Related

• BKK airport
• SFO airport