Flights San Francisco → Ontario
As of October 2026, economy flights from San Francisco to Ontario have a typical range TWD 3806–12534, median TWD 8930. Full range across all 218 offers: TWD 2470–72860. We analyzed 218 offers from 7 airlines in a single price check.
Preview snapshot — prices change. Search for live results.
Data collected by LetsFG's multi-source price checks — every airline and the major booking sites checked for this route. How we collect data →
Best offers by airline: San Francisco → Ontario
Based on 218 offers · October 2026. Prices and availability change — run a live search to confirm.
Bag & seat fees: San Francisco → Ontario
Add-on pricing from the cheapest available offer per airline · October 2026 · TWD
| Airline | Carry-on | Checked bag | Seat selection |
|---|---|---|---|
| Frontier Airlines | — | — | — |
| United | Included | TWD 35 | — |
| Southwest Airlines | Included | Included | — |
| American Airlines | Included | TWD 35 | — |
| Alaska Airlines | Included | TWD 35 | — |
| Delta | Included | TWD 35 | — |
Fees are estimates from the prices we checked and may not reflect your specific itinerary, booking class, or payment method. Run a live search for exact pricing.
How much do flights from San Francisco to Ontario cost?
Based on 218 offers · October 2026
San Francisco to Ontario flights ranged from TWD 2470 to TWD 72860 across 218 offers analyzed in October 2026. The chart below shows how prices distributed across all 218 offers.
These 218 offers (October 2026) span multiple departure dates and booking windows — your travel dates may fall anywhere in this distribution. Only a live search shows where your specific trip lands.
50% of offers priced between TWD 7486 and TWD 11136
What hidden fees do San Francisco to Ontario flights charge?
Ancillary fees — bags, seat selection, and payment surcharges — can add 10–25% to the base fare on San Francisco to Ontario routes. The breakdown below is based on 218 offers analyzed in October 2026.
| Carrier | Avg fee (TWD) | % of base fare |
|---|---|---|
| F9 | 10 | 0% |
| UA | 45 | 1% |
| WN | 0 | 0% |
| AA | 45 | 0% |
| AS | 45 | 0% |
| DL | 45 | 0% |
United Airlines: base ~TWD 3761 + fees TWD 45 = ~TWD 3806 total. Frontier Airlines: base ~TWD 8561 + fees TWD 10 = ~TWD 8571 total.
United Airlines's TWD 45 ancillary fees narrow the gap with Frontier Airlines's lower-fee model — the TWD 4800 base difference shrinks to TWD 4765 after fees. Always compare total cost, not just the advertised base fare.
Estimates based on median total minus average ancillary fee. Actual base fares vary by itinerary.Fee levels vary significantly across carriers on this route — some carriers charge 50%+ above the base fare in ancillary fees.
Run your search to see itemized fees for your itineraryWhich airline is cheapest from San Francisco to Ontario?
7 airlines flew San Francisco to Ontario in this dataset. Knowing the airline isn't enough — the typical fare range below shows how far prices swing on each one. Median and range include all fees we recorded.
Even on the cheapest airline (Frontier), fares ranged TWD 2470–3938 in this snapshot. Your exact price depends on your dates and how far ahead you book — run a live search to see your number →
| Airline | Offers | Typical range (TWD) | Median (TWD) | Fees (TWD) |
|---|---|---|---|---|
 Frontier | 12 | 2470–3938 | 3639 | n/a |
 United Airlines | 9 | — | 3806 | 45 (1%) |
 Frontier Airlines | 38 | 3904–10028 | 8571 | 10 (0%) |
 Southwest Airlines | 120 | 7313–11153 | 8649 | 0 (0%) |
 Alaska Airlines | 16 | 11879–12189 | 12091 | 45 (0%) |
 American Airlines | 12 | 11152–24661 | 13147 | 45 (0%) |
 Delta Air Lines | 11 | 56132–71883 | 71883 | 45 (0%) |
Where do the best San Francisco → Ontario prices come from?
We checked direct airlines, travel agencies, and meta-search for this route. On this route the lowest median came from travel agency sources, but the cheapest channel shifts by route and date — which is exactly why a live search across all of them wins.
We compare every airline and the major booking sites but never disclose which — that's our edge. Prices are the ones we observed and aren't official data from any platform. Run a live search and we bring you the cheapest, wherever it is.
Key facts: San Francisco to Ontario flights
- Full-service carriers on San Francisco–Ontario cost 3.6x more than budget airlines (TWD 25232 vs TWD 6953 median; overall median TWD 8930).
- UA charges 4.5x more in ancillary fees than F9 — TWD 45 vs TWD 10 avg per booking.
- The same route priced TWD 5464 apart depending on where it was booked — the lowest median was TWD 3639. We search every airline and the major booking sites at once so you always see that lowest price.
Frequently asked questions
- How much does a flight from San Francisco to Ontario cost?
- Based on 218 offers analyzed, San Francisco to Ontario flights range from TWD 2470 to TWD 72860, with a median price of TWD 8930. Search for your specific dates →
- What hidden fees should I expect on San Francisco to Ontario flights?
- On average, ancillary fees (bags, seat selection) add TWD 12 to the base fare on San Francisco to Ontario flights. See itemized fees for your itinerary →
- Which airline is cheapest on San Francisco to Ontario including all fees?
- Frontier has the lowest median fare on San Francisco to Ontario at TWD 3639 (median across 12 offers in our snapshot). Check which airline wins on your dates →
- Which booking site has the cheapest San Francisco–Ontario flights?
- It depends on your dates — no single site is always cheapest. We search every airline and the major booking sites at once (travel agencies and meta-search included) and surface whichever is lowest; the best median in this snapshot was TWD 3639. Run a live search and we'll find the cheapest for you →
- Why do prices vary so much on San Francisco to Ontario routes?
- San Francisco to Ontario has 7 airlines competing, creating a price range from TWD 2470 to TWD 72860 across 218 offers. Prices on this route change with booking timing, advance purchase, and ancillary add-ons. Find where your trip lands in the distribution →
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