Flight Time, Distance & Jet Lag Calculator
Estimate flight time, distance, ground speed and the local arrival time between 40 major airports, and see how many time zones you cross and roughly how long jet lag lasts.
Written by Suhaib Hassan. Figures are estimates you can edit. Our methodology.
It measures the great-circle distance, divides by aircraft speed plus wind, adds taxi and approach time, and converts times using each airport's time zone for the date you pick.
Airlines show a scheduled time but not how it is made up. This shows distance, speed and wind so you can see what drives it.
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Block time and airborne time
Airline schedules use block time, from pushback at the departure gate to arriving at the arrival gate. It is longer than the time in the air because of taxiing, climbing and approach. Real flights also follow airways, not perfect great-circle arcs, so scheduled times are often a little longer than this estimate.
Formulas
How the numbers are worked out.
Great-circle distance
The shortest path between two points on the Earth, by the haversine formula, with Earth radius 6,371 km.
a = sin²(Δφ/2) + cos φ₁ cos φ₂ sin²(Δλ/2)
d = 2R · asin(√a)Ground speed and time
True airspeed plus the wind along the route. Airborne time is distance over ground speed.
ground speed = TAS + wind
air time = distance ÷ ground speedGate-to-gate and arrival
Airborne time plus taxi and approach minutes. Arrival is shown in the destination time zone on the departure date.
block = air time + buffer
arrival = departure + blockWorked examples
Illustrative figures, each checked by hand. The first is the default setup.
JFK to London
Widebody at 490 kt, +45 kt tailwind, 30 min buffer, departing 19:00.
ground speed 490 + 45 = 535 kt
air time = 2,991 ÷ 535 = 5.59 h (5 h 35 m) + 30 m = 6 h 05 m
No wind
Same route, calm air.
+ 30 m = 6 h 36 m
Time zone change
New York (UTC−5 in winter) to London (UTC+0).
eastbound recovery about 1 hour per day, so roughly 5 days to adjust
How to estimate flight time
- Pick the origin and destination airports.
- Choose an aircraft type and the wind along the route. Eastbound jet-stream tailwinds are commonly 40 to 100 kt.
- Set the taxi and approach allowance, then enter the departure date and local time.
- Read the gate-to-gate time, local arrival and time zone change.
Estimates only. Actual flight time depends on the routing, winds aloft, air traffic control and the aircraft. Use the airline's schedule for planning connections.
By Suhaib Hassan · Reviewed 29 September 2026 · How CalculatePilot verifies formulas →
Sources
- ICAO, Annex 2 and Annex 6, definitions of block time and flight time.
- Sinnott, R.W., Virtues of the Haversine, Sky and Telescope, 1984.
- Eastman & Burgess, How to travel the world without jet lag, Sleep Medicine Clinics, 2009.
Frequently asked questions
How is flight time calculated?
The great-circle distance is divided by ground speed (aircraft speed plus wind along the route). Taxi, climb and approach time is then added to give a gate-to-gate figure.
Why is the flight home longer?
In the middle latitudes the jet stream blows west to east, so eastbound flights get a tailwind and westbound flights a headwind. Transatlantic westbound trips are often about an hour longer.
What is block time?
The time from leaving the departure gate to arriving at the arrival gate. It is what airline timetables show.
How long does jet lag last?
A common rule of thumb is about one day per time zone crossed when travelling east and about two-thirds of a day per zone travelling west. It varies a lot between people.
Why does the arrival day sometimes change?
Crossing the date line or a long eastbound flight can land on a different calendar day in the destination time zone. For jet lag, a 17 hour clock difference counts as 7 hours the other way round the world.
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