Flight Duration Calculator

Why you cannot just subtract the two times

Airlines publish departure and arrival times in the local time of each airport. Subtract one from the other across a time-zone boundary and the answer is wrong by the offset between them, which is why a westbound transatlantic flight appears to land barely after it took off, and why the return looks like it takes twice as long.

This calculator takes the departure and arrival times as printed on your ticket, plus the UTC offset of each airport, and returns the actual elapsed time in the air. Enter the offsets as they apply on your travel date, not as a general rule for the country: much of the world shifts by an hour for part of the year, and the two ends of a long flight do not necessarily change on the same dates. The Time Zone Converter will tell you the offset in force.

A worked example

A flight leaves at 10:00 from an airport at UTC+2 and lands at 12:30 at an airport at UTC−4. Converted to a single clock, departure is 08:00 UTC and arrival is 16:30 UTC, so the flight takes 8 hours 30 minutes: not the 2 hours 30 minutes the printed times suggest. The direction of travel makes no difference to the method: it is always arrival minus departure, once both are on the same clock.

What the number includes, and what it does not

The result is gate-to-gate block time for the sector you entered. It does not include the time you spend on the ground in a connection, and it says nothing about check-in, security or immigration at either end.

For an itinerary with a change of plane, calculate each sector separately and add the layover between them. The layover is where journeys go wrong, and the figure worth checking is not the one the booking engine accepted but the minimum connection time published for that airport: it varies by terminal, and by whether the connection is domestic or international. A connection that requires clearing immigration and re-checking bags needs substantially more slack than one airside in the same terminal.

Using the answer

Judging a fare. Two itineraries with the same total elapsed time can differ by hours in the air. Working out the flying time for each sector shows you where a cheaper fare is actually costing you: a long layover is time, a long flight is fatigue, and they are not interchangeable.

Planning arrival day. Elapsed flying time, not the clock at your destination, is what determines how you will feel on landing. A flight that lands at 09:00 local after nine hours overnight is a very different proposition from one that lands at 09:00 after two hours.

Anticipating jet lag. The direction and size of the offset change matter more than the duration. Eastward travel compresses the day and is generally harder to adjust to than westward travel across the same number of zones. Crossing several zones on a short flight — as on some north-south routes — barely affects you; crossing eight on a long one will.

Timing what happens next. If someone is meeting you, or you have booked a transfer, give them the arrival time in their local clock, and add realistic time for immigration and baggage on top of the landing time.

Checking your inputs

Two mistakes account for most wrong answers. The first is using the wrong offset: the standard-time offset when daylight saving is in force, or vice versa. The second is overlooking an overnight flight that lands on the following calendar day; if the arrival date is not the departure date, make sure that is reflected in what you enter.

Related tools

The Distance Calculator gives the great-circle distance between two points, which is a useful sanity check: a flight cannot be much faster than the distance divided by a typical cruising speed. For the local time at either end, see the Time Zone Converter, and for the practical planning sequence around a trip, Plan Your Trip.