Flight Duration Calculator
Enter departure and arrival local times (and cities) to get the true elapsed flight time.
Departure
Arrival
Why Not Just Subtract The Clock Times?
Departure and arrival times are usually given in two different local time zones. Simply subtracting the clock numbers (e.g. "9:00 AM to 9:00 PM = 12 hours") ignores the time difference between the two cities and gives the wrong answer. This calculator converts both times to a common reference point first, so the result is the true elapsed flight time.
Formula
Example
A flight departs New York at 9:00 AM EST and lands in London at 9:00 PM GMT the same day. London is 5 hours ahead of New York, so 9:00 PM GMT is 4:00 PM EST — giving a true flight duration of 7 hours, not the 12 hours you'd get from naively subtracting 9:00 AM from 9:00 PM.
Frequently Asked Questions
Why is my flight duration different from arrival time minus departure time?
Because departure and arrival are usually shown in two different local time zones. The true flight duration accounts for the time zone difference between the two cities, not just the clock numbers.
Does this handle overnight flights and date changes?
Yes — enter the correct arrival date (which may be a day later than departure) and the calculator accounts for it automatically.