London to Bangkok
12h 17mgate to gate
The flight from London Heathrow Airport (LHR) to Don Mueang International Airport (DMK) covers 9,548 km (5,933 miles) and takes approximately 12h 17m gate to gate for a typical jet.
The route heads east on an initial great-circle bearing of 73°, passing near 44.3° N, 64.9° E at its midpoint.
Bearing 73° east Midpoint 44.3° N, 64.9° E Model 805 km/h + 25 min
SOURCE·OurAirports + great-circle computation·REVIEWED JUL 2026
How this is worked out
- Take both airports' published coordinates from OurAirports — nothing here is scraped from another flight site.
- Great-circle distance by haversine on a mean earth radius of 6,371.0088 km: 9,548 km.
- Airborne time = that distance ÷ 805 km/h, a representative jet cruise speed: 11h 52m.
- Add a flat 25 minutes for pushback, taxi, climb, descent and taxi-in — the reason a 400 km hop is never half an hour: 12h 17m gate to gate.
- Winds, aircraft type and airline schedule padding are not modelled. The cruise-speed table shows how much that assumption is worth.
9,548 km / 805 km/h = 11h 52m airborne
+ 25 min ground = 12h 17m gate to gate
SOURCE·OurAirports + great-circle computation·REVIEWED JUL 2026
The same route, plotted on a world grid
The strip above gives the route its length and its shape. This gives it a position: latitude and longitude only, no coastlines, because a hand-drawn coastline would be decoration pretending to be data. On a flat grid the shortest path looks bent; on a globe it is straight.
Flight time at different cruise speeds
Aircraft type, winds and routing all move the real number. This is the same distance flown at different speeds, plus the 25-minute ground and climb allowance.
| Typical of | Cruise speed | Airborne | Gate to gate |
|---|---|---|---|
| Turboprop / regional | 550 km/h | 17h 22m | 17h 47m |
| Narrowbody jet (A320, 737) | 780 km/h | 12h 14m | 12h 40m |
| Widebody jet (777, 787, A350) | 900 km/h | 10h 37m | 11h 02m |
| Private jet (Gulfstream) | 850 km/h | 11h 14m | 11h 39m |
Headwinds on an eastbound long-haul routinely add 30–60 minutes; the same route westbound can be quicker. Airlines publish schedules with padding built in.
SOURCE·OurAirports + great-circle computation·REVIEWED JUL 2026
Both airports
| LHR | DMK | |
|---|---|---|
| Airport | London Heathrow Airport | Don Mueang International Airport |
| City | London | Bangkok |
| Country | United Kingdom | Thailand |
| ICAO | EGLL | VTBD |
| Coordinates | 51.4707, -0.4599 | 13.9126, 100.607 |
| Elevation | 83 ft | 9 ft |
Every figure on this plate is geometry. The shape of the earth is knowable; the airline's schedule is not.
Questions this plate answers
How long is the flight from London to Bangkok?
A non-stop flight from London (LHR) to Bangkok (DMK) takes about 12h 17m. The great-circle distance is 9,548 km (5,933 miles, 5,156 nautical miles), flying east on an initial bearing of 73°.
How far is London from Bangkok?
9,548 kilometres in a straight line over the earth's surface — 5,933 miles or 5,156 nautical miles. Actual flown distance is usually 2–5% longer because aircraft follow airways, avoid weather and route around restricted airspace.
Is there a non-stop flight between LHR and DMK?
This page calculates the direct-line time and distance; it does not track airline schedules. At 9,548 km the route is comfortably within range of a non-stop service if an airline chooses to fly it. Check an airline or booking site for what is actually scheduled.
What should I expect on a 12h 17m flight?
Anything past six hours is a long-haul flight: expect at least one meal service, a significant time-zone shift, and enough sitting that circulation and hydration start to matter. Cabin altitude, dry air and disrupted sleep do more damage to a training routine than the flight itself.
Airport coordinates from OurAirports (public domain). Distance is a great-circle calculation; flight time uses the model described on the method page. Flight times are great-circle estimates for planning only — always check the airline's published schedule.
