Air Travel Time Calculator: Flight Duration & Distance

An air travel time calculator estimates the flight duration between two airports based on the great-circle distance and an assumed average ground speed. You enter the origin and destination (or their coordinates) and a typical cruising speed, and it returns the expected time in the air, excluding taxi, takeoff, and landing.

Formula

The core of the calculator is the haversine formula, which gives the shortest distance between two points on a sphere. For coordinates (lat1, lon1) and (lat2, lon2) in degrees, the central angle Δσ is:

Δσ = acos( sin(lat1)·sin(lat2) + cos(lat1)·cos(lat2)·cos(lon2 − lon1) )

The distance d = R · Δσ, where R is Earth’s mean radius (6,371 km or 3,959 mi). The flight time is then t = d / v, where v is the average ground speed.

Variables: lat1, lon1, lat2, lon2 in degrees; speed in km/h (or convert to mph); distance in km or mi; time in hours.

Worked Example

Using the defaults: New York (40.7128° N, 74.0060° W) to London (51.5074° N, 0.1278° W), with a ground speed of 900 km/h.

1. Convert to radians: lat1 = 0.7106, lon1 = −1.2915, lat2 = 0.8991, lon2 = −0.00223.

2. Compute the central angle: Δσ = acos( sin(0.7106)·sin(0.8991) + cos(0.7106)·cos(0.8991)·cos(−0.00223 − (−1.2915)) ) ≈ 0.8991 rad (about 51.5°).

3. Distance = 0.8991 × 6371 ≈ 5,730 km (3,560 mi).

4. Time = 5,730 / 900 ≈ 6.37 hours (about 6 h 22 min).

The calculator’s first output rounds to 6.37 hours, matching this step-by-step result.

What the Calculator Gives You

The tool outputs three values: the flight time in hours (the headline), the great-circle distance in kilometers, and the distance in miles. You can adjust the speed to reflect a typical jet (800–950 km/h) or a slower propeller aircraft (300–500 km/h). The result is the time spent cruising, not the total door-to-door time.

Real flights are longer because of taxiing, climb, descent, holding patterns, and headwinds or tailwinds. The calculator’s estimate is a baseline; actual flight times are often 10–20% longer.

How to Use It Correctly

Enter the latitude and longitude of the departure and arrival airports. You can find these coordinates from a simple web search or an aviation database. For a quick estimate, use the city coordinates as in the default example. The speed should be the average ground speed, not the airspeed—ground speed includes the effect of wind. If you don’t know it, use 900 km/h as a typical commercial jet cruise.

For a route like Los Angeles to Tokyo, the great-circle distance is about 8,800 km, so at 900 km/h the flight time would be about 9.8 hours. With a headwind, it could be 10.5 hours; with a tailwind, 9.2.

Common Mistakes and Limitations

One frequent error is using airspeed instead of ground speed. Airspeed is relative to the air mass, while ground speed is relative to the ground. A 100 km/h headwind reduces ground speed by 100 km/h, increasing flight time.

Another mistake is using a flat map distance. The great-circle path is shorter than a straight line on a Mercator projection, especially for transoceanic routes. The haversine formula assumes a perfect sphere; Earth is an oblate spheroid, but the error is less than 1%.

The calculator ignores climb and descent, which add about 10–15 minutes for a short flight and 20–30 minutes for a long one. It also ignores air traffic control routing, which may deviate from the great circle.

Why Use a Great-Circle Distance?

On a flat map, the shortest route looks curved because of map projection. In reality, the shortest path between two points on a sphere is an arc of a great circle—a circle whose center coincides with Earth’s center. For example, a flight from New York to Hong Kong goes over the Arctic, not straight across the Pacific, because that’s shorter. The haversine formula captures this accurately.

Pilots and airlines use great-circle routes for fuel efficiency, but they often adjust for winds and airspace restrictions. The calculator gives the ideal, no-wind distance and time.

Frequently Asked Questions

How accurate is this calculator?

It is accurate to within a few percent for the cruising portion, assuming you enter correct coordinates and a realistic ground speed. Actual flight times can be 10–20% longer due to taxi, climb, descent, and weather.

What ground speed should I use?

For a commercial jet, use 850–950 km/h (530–590 mph). For a small propeller plane, use 250–350 km/h (155–220 mph). If you have a specific flight, check the typical ground speed from a flight tracker.

Does the calculator include takeoff and landing?

No, it only computes the time in the air at cruising speed. Add about 15–30 minutes for taxi and climb/descent to get a realistic door-to-door estimate.

Why does the distance differ from what my airline shows?

Airlines often use slightly different coordinates or account for flight paths that deviate from the great circle. Also, they may report the distance in nautical miles. The calculator uses the standard great-circle distance in kilometers and miles.

Can I use this for any two points on Earth?

Yes, as long as you have the latitude and longitude. It works for any pair of coordinates, not just airports.

How do I convert the time to hours and minutes?

Take the decimal part and multiply by 60. For example, 6.37 hours is 0.37 × 60 = 22 minutes, so 6 h 22 min.

Related

• Age Calculator in Years, Months, and Days Online
• Age Calculator With Time: Years, Months, Days and Hours
• Age Calculator Years and Months: How It Works

in dep | Departure latitude | deg | 40.7128 | -90
in depLon | Departure longitude | deg | -74.0060 | -180
in arr | Arrival latitude | deg | 51.5074 | -90
in arrLon | Arrival longitude | deg | -0.1278 | -180
in speed | Ground speed | km/h | 900 | 100
out hours | Flight time | h | acos(sin(dep*pi/180)*sin(arr*pi/180)+cos(dep*pi/180)*cos(arr*pi/180)*cos((arrLon-depLon)*pi/180))*6371/speed | 2
out distance | Great-circle distance | km | acos(sin(dep*pi/180)*sin(arr*pi/180)+cos(dep*pi/180)*cos(arr*pi/180)*cos((arrLon-depLon)*pi/180))*6371 | 0
out miles | Distance in miles | mi | out.distance * 0.621371 | 0