A flight from London (LHR) to Chicago (ORD) typically takes about 8 h 55 min. The return, Chicago to London, takes about 7 h 40 min. The distance is 6,345 km (3,942 miles) along the great-circle path.
The jet stream, a fast river of air at cruising altitude, blows mostly from west to east. Flying Chicago to London you ride it, about 7 h 40 min; flying London to Chicago you fly into it, about 8 h 55 min. It is the same distance either way, which is why the westbound leg is usually the longer one.
Chicago is 6 hours behind London (standard time; the gap shifts by an hour for part of the year when only one of them is on daylight saving). Leave London at 10:00 and you land at about 12:54 Chicago time, the same day.
Chicago is 6 hours behind, so your body clock has to run later. That is the easier direction: with no plan, expect about 4 days to feel properly adjusted.
For two or three days before, go to bed and get up an hour later each day, and get bright light in the evening. Even a partial shift helps.
Set your watch to Chicago time as you board. On a typical morning departure you land around 12:54 Chicago time, in daylight: sleep only if it is night in Chicago, drink water, go easy on alcohol, and then stay up until local bedtime.
Get outdoor light in the afternoon and evening, and stay up until local bedtime. Keep any nap under 30 minutes, early in the day.
General guidance, not medical advice. If you have a health condition or take medication, ask your doctor before changing your sleep routine.
Range decides what can do this route without a stop. At 6,345 km it is within reach of Airbus A321LR, Boeing 787-9, Airbus A350-900 and Boeing 777-300ER.
| Aircraft | Approx. range | Estimated LHR–ORD |
|---|---|---|
| Airbus A320neo | 6,300 km | needs a stop |
| Boeing 737-800 | 5,400 km | needs a stop |
| Airbus A321LR | 7,400 km | 8 h 50 min |
| Boeing 787-9 | 14,100 km | 8 h 15 min |
| Airbus A350-900 | 15,000 km | 8 h 15 min |
| Boeing 777-300ER | 13,650 km | 8 h 10 min |
Distance is the great-circle distance between London Heathrow and Chicago O'Hare. Time is that distance at about 830 km/h cruise, adjusted for the prevailing jet stream, plus roughly 35 minutes for taxi, climb and descent. It is a typical scheduled-time estimate, not a timetable: airlines publish their own, and daily winds, routing and air traffic can move a long flight by half an hour or more. Reviewed October 2026.
About 8 h 55 min from LHR to ORD. The return flight is about 7 h 40 min.
From London to Chicago it is typically about 8 h 55 min, covering 6,345 km.
6,345 km (3,942 miles, 3,426 nautical miles) in a straight line.
The jet stream blows west to east, so the eastbound flight is shorter than the westbound one. The distance is identical.
Chicago is 6 hours behind London in standard time.
At 6,345 km it is within the range of long-haul airliners such as the Boeing 777-300ER, so a non-stop flight is possible; check airline schedules for what is actually operated.
Typically about 4 days with no plan, and less if you shift your sleep and light exposure to local time.
Shift your sleep an hour later for two or three days before you fly, switch to destination time on boarding, stay awake until local bedtime on arrival, and get outdoor light in the afternoon and evening.
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