Flight Duration Calculator
Enter departure and arrival local times with their UTC offsets to find the actual flight duration.
UTC offsets are in hours (e.g. -5 for US Eastern, +1 for Central European Time).
How flight duration is calculated across time zones
A flight's displayed departure and arrival times are both in local time at their respective airports, which can be misleading when the two time zones differ. This calculator converts both local times to a common reference (UTC) using the time zone offsets you provide, then finds the actual elapsed time between them.
This is why a flight can show an arrival time earlier in the day than its departure time, or a trip can appear to take much longer or shorter than it actually did — the displayed clock times don't account for the time zone change on their own.
Frequently asked questions
Why would a flight's arrival time be 'before' its departure time?
When flying westward across time zones, local clocks move backward relative to the origin, so a long eastbound or westbound flight can show an arrival clock time that looks earlier than the departure time — even though real elapsed time has passed. Converting both to UTC removes this illusion.
Where do I find a flight's UTC offset?
Each airport's time zone has a standard UTC offset (which may shift for daylight saving time depending on the date). Check the departure and arrival cities' current offset for your travel date before using this calculator.
Does this calculator account for layovers?
No — this finds the elapsed time between one departure and one arrival. For a multi-leg trip with layovers, calculate each flight segment separately, or use the first departure and final arrival to find total door-to-door travel time including layover time.