On This Page
- How to Use This Calculator
- What Is Great-Circle Distance?
- How Flight Time and Distance Are Calculated
- CO₂ and the Environmental Cost of Flying
- Timezone Differences on Long-Haul Routes
- Worked Examples: International Flight Distance
- Frequently Asked Questions
How to Use This Calculator
This air flight distance calculator finds the direct great-circle distance between any two airports in km, miles, and nautical miles. Type a city name, airport code, or country into either search box. A dropdown shows up to eight matching airports with their IATA code and location. Click the one you want, then do the same for the destination. Results update automatically once both airports are selected.
The calculator produces four outputs: distance between airports in km and miles, estimated total flight time (including boarding and taxi buffer), CO₂ per economy passenger, and the current timezone gap between origin and destination.
The swap button reverses origin and destination without re-typing. Distance is the same in both directions, but the timezone display flips to show the relationship from the new perspective.
All calculations run in your browser. No data is sent to any server. You can use this page offline once it has loaded.
What Is Great-Circle Distance?
The shortest path between any two points on a sphere is an arc of a great circle, a circle whose center matches the center of the sphere. On Earth, that means the shortest route between two airports curves through higher latitudes rather than following a straight line on a flat map.
This is why flights between Europe and North America arc over Greenland and the North Atlantic, even though a straight line on a standard world map would appear to pass much further south. The map lies. The globe is telling the truth.
This calculator uses the Haversine formula, the standard method for computing great-circle distance from latitude and longitude coordinates. It is accurate to within a few kilometers for any pair of airports on Earth. Actual flight paths deviate slightly because of airspace restrictions, wind patterns (jet streams), and airline route preferences, but great-circle distance gives a reliable baseline for planning and comparison.
For reference, 1 kilometer equals approximately 0.621 statute miles or 0.540 nautical miles. Airlines measure distances in both kilometers and nautical miles depending on region. Frequent-flyer programs typically award miles in statute miles regardless of the unit the airline uses for fuel calculations.
Calculating flight distance between cities follows the same method regardless of whether you are comparing domestic routes, international connections, or long-haul intercontinental services. The Haversine formula treats the Earth as a sphere with a radius of 6,371 km. The real Earth is slightly flattened at the poles, but the difference is less than 0.5 percent and negligible for flight planning purposes.
Flight path distance and flight route distance refer to slightly different things. Flight path distance is the great-circle distance, the theoretical minimum route. Flight route distance is the actual path flown, which is typically 2 to 8 percent longer due to airspace restrictions, standard instrument departures, oceanic track systems, and airways structure. This flight distance calculator gives the direct flight path distance as a clean planning baseline for any pair of airports.
How Flight Time and Distance Are Calculated
Cruise speed for a modern wide-body jet (Boeing 777, Airbus A350, Boeing 787) sits around 900 km/h at altitude. Narrowbody jets on shorter routes fly slightly slower, roughly 800 to 850 km/h, but the difference is small for most route comparisons.
Raw cruise time alone understates the real journey time. Every flight includes ground taxi, takeoff roll, climb to cruise altitude, descent, approach, and landing roll before passengers can disembark. This calculator adds a buffer based on route length:
- Short routes (under 1,500 km): 45-minute buffer for taxi, takeoff, descent, and landing.
- Medium routes (1,500 to 6,000 km): 60-minute buffer.
- Long-haul routes (over 6,000 km): 90-minute buffer, accounting for longer climbs and descents on transcontinental services.
Actual block time, the time an airline publishes from gate departure to gate arrival, can vary further due to prevailing winds, air traffic control routing, and slot restrictions at busy airports. Eastbound transatlantic flights are often an hour shorter than westbound due to the jet stream. This calculator gives a planning estimate, not a published schedule.
Check the Work Hours Calculator if you need to add flight time to a shift or calculate total working hours across a journey with timezone changes.
CO₂ and the Environmental Cost of Flying
Aviation CO₂ figures are more complicated than a simple fuel burn divided by seat count. The real climate impact of flying includes non-CO₂ effects: contrails, water vapor, and nitrogen oxides at altitude all have warming effects beyond the CO₂ alone. Scientists apply a radiative forcing multiplier to capture these additional effects in a single CO₂-equivalent figure.
This calculator uses the following economy-class, one-way emission factors, which include radiative forcing:
- Short-haul (under 1,500 km): 0.255 kg CO₂ per km per passenger.
- Medium-haul (1,500 to 4,000 km): 0.195 kg CO₂ per km per passenger.
- Long-haul (over 4,000 km): 0.145 kg CO₂ per km per passenger.
Short-haul flights have a higher per-km factor because the climb phase, where fuel burn per kilometer is highest, makes up a larger proportion of the total flight. A 400 km hop burns more fuel per seat-kilometer than a 10,000 km transoceanic service.
Business and first class passengers have a larger carbon footprint per person because their seats take up more physical space on the aircraft, reducing total capacity. Estimates typically multiply economy figures by 1.5 to 2.5 for business class and 2.5 to 4 for first class.
To put the numbers in context: a transatlantic flight (LHR to JFK) produces roughly 780 to 900 kg CO₂ per economy passenger, which is comparable to driving a petrol car for about 5,000 to 6,000 km.
Timezone Differences on Long-Haul Routes
The timezone display shows the current offset between origin and destination cities based on your device clock and the IANA timezone database. This accounts for daylight saving time automatically, so a London to New York flight in summer shows a 5-hour difference while in winter it shows 5 hours as well (both observe their respective daylight saving shifts).
Knowing the timezone gap matters for planning. A midnight departure from London lands in New York around 2 am local time, which is 7 am body-clock time for a passenger who did not sleep. A 14-hour flight from London to Sydney crosses 9 to 11 time zones depending on the season, making it one of the most disorienting routes for jet lag.
Some routes cross unusual fractional offsets. India is UTC+5:30. Nepal is UTC+5:45. Iran is UTC+3:30. The Time to Decimal Calculator can help convert these half-hour and quarter-hour offsets to decimal form for scheduling calculations.
Airline crews flying east across the Pacific can gain or lose an entire calendar day depending on whether they cross the International Date Line going outbound or returning. A flight from Los Angeles to Sydney departing on a Monday typically arrives on Wednesday, skipping Tuesday entirely.
Worked Examples: International Flight Distance Between Cities
Example 1: London (LHR) to New York (JFK)
LHR coordinates: 51.47°N, 0.45°W. JFK coordinates: 40.64°N, 73.78°W.
Great-circle distance: approximately 5,539 km (3,442 mi). At 900 km/h cruise speed, raw air time is about 6 h 11 min. Adding a 60-minute medium-haul buffer gives an estimated block time of roughly 7 h 11 min. CO₂ per economy passenger: approximately 1,080 kg (at 0.195 kg/km). Timezone: New York is 5 hours behind London in summer, 5 hours behind in winter.
Example 2: Dubai (DXB) to Sydney (SYD)
DXB coordinates: 25.25°N, 55.37°E. SYD coordinates: 33.95°S, 151.18°E.
Great-circle distance: approximately 12,036 km (7,480 mi). This is one of the world's longest commercial routes. Raw air time at cruise speed is about 13 h 22 min, and a 90-minute long-haul buffer gives a block time estimate of roughly 14 h 52 min. CO₂ per economy passenger: approximately 1,745 kg (at 0.145 kg/km). Sydney is 6 to 7 hours ahead of Dubai depending on whether Australia is observing summer time.
Example 3: Paris (CDG) to Singapore (SIN)
CDG coordinates: 49.01°N, 2.55°E. SIN coordinates: 1.36°N, 103.99°E.
Great-circle distance: approximately 10,742 km (6,676 mi). Block time estimate: roughly 13 h 48 min including the 90-minute buffer. CO₂ per economy passenger: approximately 1,558 kg. Singapore is UTC+8, Paris is UTC+1 (UTC+2 in summer), giving a 7 or 6-hour gap depending on season.
Example 4: Los Angeles (LAX) to Tokyo (NRT)
LAX coordinates: 33.94°N, 118.41°W. NRT coordinates: 35.77°N, 140.39°E.
Great-circle distance: approximately 8,815 km (5,477 mi). Block time estimate including the 90-minute buffer: roughly 11 h 39 min. CO₂ per economy passenger: approximately 1,278 kg. Tokyo is 17 hours ahead of Los Angeles in summer (UTC+9 vs UTC−8). Westbound flights often take 90 minutes longer than eastbound due to headwinds.
Example 5: Johannesburg (JNB) to London (LHR)
JNB coordinates: 26.14°S, 28.25°E. LHR coordinates: 51.47°N, 0.45°W.
Great-circle distance: approximately 9,005 km (5,595 mi). Block time estimate: roughly 11 h 52 min. CO₂ per economy passenger: approximately 1,306 kg. London is 2 hours behind Johannesburg (UTC+0 vs UTC+2), making late-evening Johannesburg departures arrive in London in the early morning.
Frequently Asked Questions
How accurate is great-circle distance for real flights?
Very accurate as a baseline. Real flight paths deviate by 2 to 8 percent due to wind routing, airspace restrictions, and procedural requirements. The great-circle figure gives the shortest physically possible route between two airports. Airlines fly close to it on favourable winds and diverge on headwind routes.
Why does my flight take longer westbound than eastbound?
The jet stream is a fast-moving band of air at cruise altitude that blows predominantly from west to east at 100 to 250 km/h. Eastbound aircraft ride this tailwind and arrive faster. Westbound aircraft fly against it, adding time. The effect is most pronounced on transatlantic routes and can mean a difference of 1 to 2 hours each way.
What does IATA code mean?
IATA stands for International Air Transport Association. IATA codes are three-letter identifiers assigned to airports worldwide. LHR is London Heathrow. JFK is John F. Kennedy in New York. DXB is Dubai International. They are used on boarding passes, baggage tags, and booking systems to eliminate ambiguity between airports with similar names.
Why are short flights worse for CO₂ per kilometer?
The climb phase burns the most fuel per kilometer because the aircraft is fighting gravity to gain altitude. On a 500 km flight, the climb and descent phases might account for 40 to 60 percent of total fuel burn. On a 12,000 km flight, those same phases are only a small fraction of the total. This makes short flights far less efficient per seat-kilometer than long-haul services.
Does the calculator include connecting flights?
No. Each calculation covers a single non-stop route between two airports. For connecting itineraries, calculate each leg separately and add the distances and times together. Note that CO₂ should be summed per leg, not recalculated on the total distance, since each landing and takeoff carries its own fuel penalty.
How many airports are included in the search?
Around 250 major airports covering North America, Europe, Asia, the Middle East, South America, Africa, and Oceania. All codes, city names, and coordinates are real. If your specific airport is not listed, searching by the nearest hub city will give a close estimate for most planning purposes.
How do I calculate flight distance for a compensation claim?
Under EU Regulation 261/2004, compensation for delays and cancellations is banded by flight distance. Flights up to 1,500 km qualify for €250 per passenger. Flights between 1,500 and 3,500 km qualify for €400. Flights over 3,500 km qualify for €600. To calculate flight distance for a compensation claim, use the great-circle distance between the departure airport and the final destination airport as listed on your ticket, not any intermediate stop on a connecting itinerary. Airlines sometimes dispute compensation on routes close to a threshold, so an independent calculation using the departure and arrival coordinates is useful supporting evidence. This flight distance calculator gives the direct distance between any two airports in kilometers, which is the figure airlines and dispute resolution services use for EU261 assessments.
What is crow flight distance and how does it differ from road distance?
Crow flight distance, also called as-the-crow-flies distance or straight-line distance, is the shortest possible path between two points on the Earth's surface without following roads, rivers, or other infrastructure. It is equivalent to great-circle distance on a sphere. Flight distance between airports is essentially crow flight distance: aircraft follow routes as close to the direct path as air traffic control and weather allow. Road distance is always longer because roads must follow terrain, cross bridges, and navigate built-up areas. For continental routes, road distance is typically 1.2 to 1.4 times the crow flight distance. For routes that cross large bodies of water or mountain ranges, the ratio is much higher. Use the Distance Calculator with latitude and longitude coordinates to calculate crow flight distance between any two specific points, not just airports.
What speed does the calculator use for flight time?
900 km/h, which represents typical cruise speed for a modern wide-body jet such as a Boeing 787 or Airbus A350 at high altitude. Narrowbodies on shorter routes fly at 820 to 870 km/h. The calculator also adds a boarding and taxi buffer of 45 to 90 minutes depending on route length.
Are business class CO₂ emissions higher?
Yes, considerably. Business class seats occupy more floor space and often recline flat, reducing the number of passengers per aircraft. Most carbon calculators multiply the economy figure by 1.5 to 2.5 for business class and 3 to 4 for first class. This calculator shows economy figures as a baseline. For business-class travel, multiply the displayed CO₂ figure by approximately 2.
What are nautical miles and do airlines use them?
One nautical mile equals 1.852 km or 1.151 statute miles. Nautical miles are derived from the circumference of the Earth: one nautical mile equals one minute of arc of latitude. Pilots and air traffic controllers use nautical miles for navigation and separation standards. Airlines and frequent-flyer programs in the United States and United Kingdom often cite statute miles on loyalty program statements, while European and Asian programs tend to use kilometers.
References
- ICAO Carbon Emissions Calculator Methodology: the International Civil Aviation Organization's framework for per-passenger CO₂ estimation including radiative forcing factors.
- Great-circle distance, Wikipedia: derivation and properties of the Haversine formula for spherical geometry.
- OurAirports data: open airport database providing IATA codes, coordinates, and timezone references for airports worldwide.