Flight Distance & Duration Calculator

Great Circle Distance Aircraft fly along great circle routes, the shortest path between two points on a sphere. A great circle is any circle whose center coincides with the center of the Earth, like the equator or any line of longitude. Flying a great circle is not the same as flying a straight line on a flat map. The shortest path curves toward the poles. That is why trans-Pacific flights from the US West Coast to Japan fly over Alaska rather than heading due west.

The Haversine Formula The haversine formula calculates great circle distance from latitude and longitude: a = sin²(Δlat/2) + cos(lat1) × cos(lat2) × sin²(Δlon/2) c = 2 × atan2(√a, √(1−a)) d = R × c Where R = Earth’s mean radius = 6,371 km (3,959 miles). Δlat and Δlon are differences in radians. The haversine formula is accurate for distances up to thousands of kilometers and is numerically stable even for very short distances.

Flight Duration Calculation Commercial airliners cruise at 850–900 km/h (520–560 mph) at altitudes of 10,000–12,000 meters.

Air time = great circle distance ÷ cruise speed. That is the number this calculator reports first.

Block time is what the airline puts in the timetable, and it is longer. It runs from pushback to arrival at the gate, so it includes taxi out, the queue for the runway, climb, descent, approach, and taxi in. The pad this calculator adds:

Headwinds and tailwinds move the air time more than anything else on a long route. Jet streams at altitude run 150–300 km/h, which is why the same transatlantic pair is routinely an hour shorter eastbound than westbound. The cruise speed box is where you account for that: drop it to 800 for a westbound winter crossing, raise it to 950 for the eastbound return.

Practical Examples of Great Circle Routes London to New York: 5,570 km (3,460 miles), over the North Atlantic, typically 7–8 hours westbound. Los Angeles to Sydney: 12,074 km (7,503 miles), about 15–16 hours, one of the world’s longest routes. Dubai to New York (Emirates EK201): 11,015 km (6,845 miles), approximately 14 hours eastbound. Singapore to Newark (Singapore Airlines SQ22): 15,349 km (9,537 miles), the longest scheduled non-stop flight, about 18–19 hours.

Fuel and Emissions A typical Boeing 737 burns roughly 2,500–3,000 liters of jet fuel per hour at cruise, and a Boeing 777 burns 6,000–8,000. The calculator estimates burn from your cruise time using those figures, so it is a rough order of magnitude rather than a flight-plan number. Real burn depends on payload, altitude, temperature, and how long you spend holding.

Divide it by the seats and the per-passenger number is smaller than people expect: a 737 with 180 seats burning 2,750 litres an hour uses about 15 litres per passenger per hour, which is roughly what a car uses in an hour at motorway speed carrying one person.

Short-haul flights are markedly less efficient per kilometer, because takeoff and climb burn a fixed lump of fuel that a short cruise cannot spread thin.

An economy seat on a transatlantic crossing of about 5,570 km works out near 0.8 tonnes of CO₂, or roughly 1.6 tonnes once high-altitude warming effects are counted. Business class multiplies that by about three. The flight carbon calculator does this properly with distance bands and cabin class.

The Flat Earth Misconception On a Mercator map projection, great circle routes appear to curve. This is because Mercator preserves shape but not distance. The route appears curved simply because the map distorts distances at high latitudes. In reality, the path is the straightest possible line on a spherical Earth.