Drag marker A or B anywhere on the map. The blue line is the shortest path over the globe, the grey one the straight line on the flat map; the distance updates as you move them.
You can also type the coordinates here.
- Distance at 850 km/h
- 6h 34m
- Take-off and landing
- + 30m
- Flight time
- 7h 4m
How long does a flight take? The calculator answers with a simple rule: the straight-line distance at a cruising speed of 850 km/h, plus up to 30 minutes for take-off and landing. Dividing the distance by the speed alone works for long flights but falls well short on short ones: Madrid to Barcelona, 506 km, would come out at 36 minutes, when the plane actually spends about an hour in the air. Drag the two points on the map above to get the estimate for any route.
The formula
- d is the straight-line (great-circle) distance between the two places, computed with the haversine formula.
- 850 km/h is a typical cruising speed for a commercial jet. An Airbus A320 or a Boeing 737 cruises at about 830–850 km/h; long-haul aircraft such as the Boeing 787 or the Airbus A350 fly a little faster, around 900 km/h.
- 30 minutes is the allowance for the parts of the flight spent well below that speed, on a flight long enough to reach cruise. It is the same figure most flight-time calculators use.
- 400 km is roughly the ground a jet covers climbing to cruising altitude and coming back down. Shorter flights get a proportionally smaller allowance, as explained below.
Why add 30 minutes
It works like a motorway trip: the speed limit tells you how fast you go once you are on the motorway, not how long it takes to get on and off. A plane spends the first 20 minutes or so climbing to around 10,000 metres and the last 20 to 30 minutes descending and lining up with the runway, much slower than at cruise. It still covers ground during those phases, so it does not lose the full 40–50 minutes; compared with flying the whole way at cruising speed, the time lost comes to roughly half an hour.
Those 30 minutes weigh very differently depending on the length of the flight:
| Route | Distance | At 850 km/h | Take-off and landing | Estimated flight time |
|---|---|---|---|---|
| Madrid – Barcelona | 506 km | 36 min | + 30 min | 1 h 6 min |
| Sydney – Melbourne | 714 km | 50 min | + 30 min | 1 h 20 min |
| Delhi – Mumbai | 1,149 km | 1 h 21 min | + 30 min | 1 h 51 min |
| New York – London | 5,576 km | 6 h 34 min | + 30 min | 7 h 4 min |
| Buenos Aires – Madrid | 10,057 km | 11 h 50 min | + 30 min | 12 h 20 min |
On Madrid–Barcelona, take-off and landing are almost half of the flight; on Buenos Aires–Madrid, 4%. That is why dividing the distance by the speed is good enough for a long-haul flight and badly off for a short one.
On a trip with stops, every leg has its own take-off and landing, so the calculator adds the allowance once per leg: a route through three places, with legs of 400 km or more, adds an hour.
Short flights
A 100 km flight cannot spend half an hour taking off and landing: the plane never reaches cruise. It climbs for a few minutes, levels off low and starts its descent almost at once. So under 400 km the calculator scales the 30 minutes down with the distance:
| Distance | At 850 km/h | Take-off and landing | Estimated flight time |
|---|---|---|---|
| 100 km | 7 min | + 8 min | 15 min |
| 200 km | 14 min | + 15 min | 29 min |
| 300 km | 21 min | + 23 min | 44 min |
| 400 km | 28 min | + 30 min | 58 min |
Under 100 km the calculator shows no flight time at all, and neither does a route with any leg that short. At that distance nobody takes a plane: by the time you have got through the airport you could have driven there.
Why the airline's timetable says something else
The estimate is time in the air between two points. The real flight can differ for reasons the distance alone cannot predict:
- Gate to gate. Timetables show block time, from leaving the gate to arriving at the gate. Taxiing at a large airport can add 10 to 20 minutes at each end.
- Wind. At cruising altitude the jet stream can blow at more than 150 km/h. Flying east across the North Atlantic with it behind you can be close to an hour faster than flying west into it, which is why New York–London is shorter than London–New York.
- The route is not a perfect arc. Airways, air traffic control and storms add distance. The International Civil Aviation Organization (ICAO), in its carbon emissions calculator, adds 50 to 125 km to the great-circle distance to account for it: a few more minutes of flying.
- Holding. At a busy airport a plane may circle for several minutes before it is cleared to land.
So the estimate is a sensible figure for comparing routes or planning a trip, not a replacement for the timetable.
Calculate it yourself
Type two cities into the calculator to get the straight-line distance, the estimated flight time and the road route on the same map. To see how the distance itself is worked out, read the plain-words introduction to the haversine formula or the haversine calculator.