Use these travel calculators to work out flight distance between airports, what the local clock will say when you land, and how long it takes to adjust to a new time zone.
Flight distance and route planning
The Flight Distance Calculator reports the great-circle distance between any two of 1,148 airports, plus the longer distance an aircraft is likely to fly once indirect routing and delays are counted. It also gives the initial bearing and a rough gate-to-gate time. The distance figures assume no wind.
Most tools report the great-circle figure and label it flight distance. It is not the same thing, and on a route like London Heathrow to New York JFK the gap is a few hundred kilometres.
Arrival times across time zones
The Flight Arrival Time Calculator converts your local departure time into local arrival time, tells you whether you land the same day, and shows the UTC offset in force at each airport on that date. It handles daylight saving at both ends and the international date line.
This matters more than it sounds. The United Kingdom and the United States change their clocks on different weekends, so for about two weeks each spring and autumn the gap between London and New York is four hours rather than five. Arithmetic done from memory lands an hour out.
Adjusting after you land
Once you know the size of the clock change, the Jet Lag Recovery Calculator estimates how long adjustment takes. A rough planning rule is about one day per time zone crossed, and eastbound travel is usually harder than westbound.
How to use these together
Start with distance to compare routes, then check arrival time to see which calendar day you actually land on, then plan recovery. If a six-hour clock change puts you into a morning meeting on the day you arrive, that is worth knowing before you book rather than after.
These are planning estimates, not quotes. Where the answer matters, use the flight time printed on your booking and check the airline’s own schedule.
