Flight time & jet lag: London to Bangkok

London to Bangkok: Route overview

This eastbound route from London to Bangkok traverses 9,577 km across the Eurasian continent, a long-haul journey of 11h 08m to 12h 31m that crosses 7 time zones — one of the more demanding jet lag corridors. Crossing 7 time zones eastbound creates significant circadian disruption. Your body's internal clock will take approximately 7 days to fully realign with Bangkok's local schedule. The route transitions between temperate and tropical climate zones, so expect a significant change in daylight duration and intensity that influences your circadian adjustment strategy.

What makes the London–Bangkok route different

Eastbound routes crossing 7 or more time zones are among the hardest for circadian adjustment because they require your body to advance its clock — effectively going to sleep earlier than it wants to, which is more difficult than staying up later.

Arrival strategy for Bangkok

After flying east across 7 time zones to Bangkok, your body will be significantly behind local time. If you arrive at 08:00 local, your body thinks it is 01:00. Prioritize getting bright morning light between 07:00 and 10:00 local time to advance your internal clock. Avoid the strong temptation to nap in the afternoon — if you must, limit it to 20 minutes. Target a local bedtime of 22:00 even if you do not feel sleepy, and avoid screens for 2 hours before.

Circadian rhythm analysis: London → Bangkok

When you arrive in Bangkok, your circadian rhythm is still running on London time. At 09:00 Bangkok time, your body clock reads 02:00 — the middle of the night. You will experience profound drowsiness during what should be your productive morning hours. By 22:00 local time (when you should sleep), your body reads 15:00 — still mid-afternoon internally. Falling asleep will be very difficult without sleep hygiene strategies. Your circadian system adjusts at roughly 1 hour per day, so expect 7 days for full alignment.

Your body clock in Bangkok (day 1)

How your body clock maps to local time upon arrival, before any adjustment.

Pre-departure preparation

To prepare for this 7-hour eastward shift to Bangkok, begin adjusting 4 days before departure. Each night, move your bedtime 105 minutes earlier and wake correspondingly earlier. Seek bright light immediately upon waking. On departure day, set your watch to Bangkok time and begin eating meals on that schedule. This pre-adjustment can reduce your recovery time by 1–2 days.

Your first 72 hours in Bangkok

Day 1 in Bangkok: Your body is ~7 hours off local time. Get bright sunlight in the morning. Avoid napping past 14:00. Eat at local mealtimes even if not hungry. Caffeine is fine before 14:00, not after. Day 2: ~6 hours off. Continue morning (07:00–10:00) light exposure. Sleep quality should improve. Day 3: ~5 hours off. Noticeable improvement. Maintain light and meal timing discipline.

Recovery timeline

Full circadian adjustment for the London → Bangkok route typically takes 7 days, based on the body's natural adaptation rate of ~1 hour per day for eastbound travel. During this period, expect gradually improving sleep quality, with the most noticeable symptoms (fatigue, difficulty concentrating, appetite changes) during the first 3 days. By day 7, most travelers report feeling fully synchronized with Bangkok's schedule.

Route Planner

Adjust departure date for DST-accurate results.

Jet lag adjustment plan: London → Bangkok

Significant jet lag. Allow 4–7 days for full adjustment. Plan sleep and light exposure carefully.

Business hours: London vs Bangkok

Seasonal and climate factors

Flight times between London and Bangkok can vary by 15–30 minutes seasonally due to shifting wind patterns along this long-haul corridor. Bangkok's tropical location (14°N) provides consistent ~12 hours of daylight year-round, making light exposure timing predictable and reliable for jet lag recovery regardless of when you travel.

How the London–Bangkok flight time is estimated

The 11h 08m to 12h 31m estimate for London to Bangkok is derived from the 9,577-km great-circle distance. Long-haul flights spend most of their duration at optimal cruise altitude (typically 35,000–40,000 feet), achieving effective speeds of 820–900 km/h. An additional 30–50 minutes accounts for taxi, takeoff, climb, descent, approach, and taxi at both LHR and BKK. Actual routing through controlled airspace may add 3–8% distance beyond the great-circle path due to air traffic corridors and restricted zones along the way.

Wind patterns and flight duration

Prevailing winds along the London–Bangkok corridor have a moderate effect on flight time. The general west-to-east flow of upper-level winds at these latitudes provides a slight tailwind advantage.

Practical travel context

This route links Europe and Asia, one of the busiest intercontinental corridors. Connections via Middle Eastern hubs (Dubai, Doha, Abu Dhabi) are common alternatives to direct flights. For stays shorter than 9 days, some travelers opt not to fully adjust to local time. Instead, they maintain a compromise schedule between origin and destination time, which can be effective for brief business trips.

Frequently asked questions: London to Bangkok

More questions about this route

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