Boston (BOS) – San Francisco (SFO)
- Distance
- 4,352 km
- 2,704 mi · 2,350 nm
- Flight time
- 6 h 35 min / 5 h 36 min
- Average gate to gate: BOS → SFO / back
- Time difference
- 3 h
- CO2 per passenger
- 508 kg
- One way, economy, incl. RF (301 kg CO2 only)
- Passengers / year
- 1,386,355
- Aug 2025 – Jul 2026 · +1.4%
- Flights / week
- 179
- Both directions, average
- Seats filled
- 85%
- 1,623,081 seats a year
- Airlines nonstop
- 4
- UA, B6, DL
Traffic: U.S. DOT, Bureau of Transportation Statistics, T-100 Segment (all carriers, scheduled service), Aug 2025 – Jul 2026. Distance: WGS-84 ellipsoid. CO2: UK DESNZ 2026 factors. Sources
The way there
- Heading from BOS
- 281°
- Heading from SFO
- 66°
- Halfway point
- 42.96, -97.64
- Great-circle km
- 4,341 km (sphere, for EU261)
- In the air BOS → SFO
- 6 h 3 min
- In the air SFO → BOS
- 5 h 5 min
- Clocks
- San Francisco is 3 h behind Boston
The estimate for a route without real times is 5 h 55 min; how it is worked out is on Sources.
Show as a table
| Month | Passengers |
|---|---|
| Aug 2025 | 136,482 |
| Sep 2025 | 119,584 |
| Oct 2025 | 128,590 |
| Nov 2025 | 100,794 |
| Dec 2025 | 102,472 |
| Jan 2026 | 83,270 |
| Feb 2026 | 76,170 |
| Mar 2026 | 97,610 |
| Apr 2026 | 111,624 |
| May 2026 | 131,340 |
| Jun 2026 | 144,881 |
| Jul 2026 | 153,538 |
Show as a table
| Month | Flights |
|---|---|
| Aug 2025 | 861 |
| Sep 2025 | 816 |
| Oct 2025 | 846 |
| Nov 2025 | 700 |
| Dec 2025 | 703 |
| Jan 2026 | 594 |
| Feb 2026 | 524 |
| Mar 2026 | 645 |
| Apr 2026 | 758 |
| May 2026 | 879 |
| Jun 2026 | 997 |
| Jul 2026 | 983 |
Airlines flying BOS–SFO nonstop
| Airline | Flights / week | Share of passengers |
|---|---|---|
| UAUnited Air Lines | 72 | 42% |
| B6JetBlue Airways | 65 | 34% |
| DLDelta Air Lines | 35 | 21% |
| ASAlaska Airlines | 6.6 | 4% |
Both directions, Aug 2025 – Jul 2026. Airlines with at least one flight a month. U.S. DOT, Bureau of Transportation Statistics, T-100 Segment (all carriers, scheduled service). Sources
Aircraft on this route
- Airbus Industrie A321-200n · 3,039 flights
- Boeing B737 Max 900 · 2,821 flights
- Airbus Industrie A321Neoxlr · 2,156 flights
- Boeing 757-200 · 992 flights
- Boeing 737-900ER · 184 flights
- Boeing 757-300 · 65 flights
- Boeing 737-800 · 20 flights
- Boeing B737 Max 800 · 17 flights
Also carried: 945 tonnes of freight and 200 tonnes of mail a year (passenger and cargo flights).
Punctuality
- On time
- 73.7%
- Arrived within 15 min of schedule
- Average delay
- 20 min
- Late arrivals count, early ones as 0
- Cancelled
- 1.6%
- Flights counted
- 9,468
- Aug 2025 – Jul 2026
| Airline | On time | Average delay |
|---|---|---|
| UAUnited Air Lines | 77.4% | 17 min |
| B6JetBlue Airways | 71% | 22 min |
| DLDelta Air Lines | 72.3% | 20 min |
| ASAlaska Airlines | 69.4% | 22 min |
Delay minutes by cause: airline 23% · aircraft arriving late 35% · air traffic system 40% · weather 3% · security 0%.
Both directions, Aug 2025 – Jul 2026. BTS Reporting Carrier On-Time Performance (US domestic flights of the larger US airlines). Sources
What passengers paid
- Average fare, Q1 2026
- $412
- One way, all cabins
- Average over a year
- $380
- Q2 2025 – Q1 2026
- Largest airline
- United Air Lines
- 39% of passengers · $432
- Lowest-fare airline
- JetBlue Airways
- 34% of passengers · $393
History, not a price to book: what the average passenger paid per one-way trip in each quarter (Q2 2025 $368 · Q3 2025 $361 · Q4 2025 $393 · Q1 2026 $412).
Fare outlook, Q1 2027: about $420, likely $373–$479
The average fare paid we expect a year after Q1 2026, the newest DOT quarter. On this route, past forecasts made this way fell inside the range 76% of the time over 21 quarters (median error 5.6%). An estimate from US DOT data: not a price you can book, not a guarantee, not advice on when to buy. How the outlook works
Cheapest quarter on this route: Q1, typically 7% below the year's average (9 years of DOT data, without 2020–21).
U.S. DOT Consumer Airfare Report, Table 1a (airline ticket sample, US domestic airport pairs). Sources
Delay compensation (EU261 / UK261)
Measured by great-circle distance: 4,341 km.
Neither EU261 nor UK261 covers this route: it neither starts nor ends in the EU, EEA, Switzerland or the UK. Other countries have their own rules (for example Canada's APPR or Brazil's ANAC rules).
Also owed for a cancellation with less than 14 days' notice or denied boarding. Not owed for extraordinary circumstances. On a connection, the distance to the final destination counts. From 23 October 2027 the EU's Regulation 2026/2202 applies; it keeps these amounts (what changes in 2027). Information, not legal advice.