Primary sources · 6
- [1] OpenFlights data — Source of the airport, airline, and route reference data (≈ 7,698 airports, ≈ 6,162 airlines, 67,663 routes captured June 2014) under ODbL v1.0 · openflights.org/data.php · Community-maintained https://openflights.org/data.php
- [2] Vincenty (1975) — Iterative geodesic-distance formula on the ellipsoid — Survey Review XXIII (176), pp. 88–93 · NGS publication · April 1975 https://www.ngs.noaa.gov/PUBS_LIB/inverse.pdf
- [3] NGA.STND.0036_1.0.0_WGS84 — Reference ellipsoid (a = 6,378,137 m, 1/f = 298.257223563) underlying every distance the calculator returns · NGA Standard, v1.0.0 · July 2014 https://earth-info.nga.mil/index.php?dir=wgs84&action=wgs84
- [4] DESNZ 2024 greenhouse-gas reporting conversion factors — Per-passenger-km kg CO₂e factors for three distance bands and four cabin classes, with the 1.9 × radiative-forcing uplift baked in · UK Department for Energy Security and Net Zero · Published June 2024 https://www.gov.uk/government/publications/greenhouse-gas-reporting-conversion-factors-2024
- [5] Sack (2010) — Jet lag — Clinical chronobiology review used for the jet-lag severity bands and recovery-rate estimates · New England Journal of Medicine 362:440-447 · February 2010 https://www.nejm.org/doi/full/10.1056/NEJMcp0909838
- [6] Google AdSense Publisher Policies — Bind us as a publisher — disclosure obligations, content restrictions, ad-placement rules · Google · Continuously updated https://support.google.com/adsense/answer/48182
AirMilesCalc is an independent, free-to-use tool that computes the canonical numbers for any flight route — distance, block time, CO₂e by cabin class, jet lag, fuel — from published formulas and open data. Every figure traces back to a primary source. Hosting will be funded by Google AdSense advertising once approved; the calculator and content stay free regardless of whether ads are showing.
What this calculator does
AirMilesCalc returns precise geodesic distance, still-air block time, per-cabin CO₂-equivalent, and route metadata for any pair of commercial airports worldwide. The 3D globe visualises the great-circle path that aircraft actually fly, and every number traces back to a primary source published openly. Unlike most free distance tools, we use the ellipsoidal Vincenty formula on WGS-84 rather than the spherical Haversine approximation.
| Output | Source / formula | Precision |
|---|---|---|
| Distance (km / mi / NM) | Vincenty 1975 on WGS-84 | 0.5 mm |
| Flight block time | Distance ÷ 850 km/h + 30–50 min ground | ±10 % typical |
| CO₂e per cabin class | DESNZ 2024 + 1.9 × RF uplift | Fleet average |
| Bearing + cardinal direction | Initial-azimuth great-circle formula | 1° rounded |
| Cruising altitude | Distance-banded reference (FL250–FL410) | Nominal |
| Jet-lag severity + recovery days | Sack 2010 chronobiology, asymmetric rates | Population mean |
| 3D globe arc + animated aircraft | globe.gl WebGL visualisation | Visual only |
Who this is for
The audience spans consumer travel, corporate sustainability, education, and aviation hobbyism. The tool is deliberately scoped to one job — compute the canonical numbers for a route, fast, and explain them. Anyone who needs a fuller flight-management system, a regulated emission report, or live airline schedules is better served elsewhere.
| Audience | Typical task | Best entry point |
|---|---|---|
| Frequent flyers | Mileage and route comparison | Calculator on / |
| Travel planners | Compare multi-stop itinerary distances | /distance/[route] |
| Business travellers | Block time + jet-lag for meeting timing | Per-route Jet Lag section |
| Sustainability teams | Per-cabin CO₂e for corporate reporting | /methodology/defra-emission-factors |
| Educators and students | Real-world geodesy and emissions math | /methodology subpages |
| Aviation enthusiasts | ULR routes, cruise speeds, globe view | /learn/longest-flights-in-the-world |
| Corporate travel managers | Distance for expense reports + carbon attribution | Per-route CO₂ breakdown |
Why we built this
Most free flight-distance calculators online are either advertising- stuffed, require account creation, or use the spherical Haversine approximation that drifts by up to 0.5 % on long polar routes. We wanted one tool that did the math properly, published the formulas, and stayed free of the dark patterns common in the travel-data consumer web. Ads will fund hosting once AdSense is approved; the editorial product itself stays free of upsells regardless.
Who runs this
I'm Sam K., the independent maintainer of AirMilesCalc. The project started as a personal habit of mine. I fly a lot — enough that “how far am I from home right now?” became the question I asked from most window seats, and enough that the annual mileage total turned into a quietly competitive number against the friends and family members who also rack up flights. The free distance tools I was using to answer those questions were either ad-cluttered, used the spherical Haversine approximation that drifts up to 0.5 % on long polar routes, or hid the good math behind a signup wall.
So I built my own, and every design choice on the site reflects what I wanted from the tool myself. Vincenty geodesic precision because the spherical-approximation rounding felt sloppy on long routes; DEFRA 2024 factors because the UK government's data was the cleanest source I could actually cite; no signup because I did not want to sign up to my own tool. The public version is the same engine I use — compute the distance between any two airports, see what that ticket emits, watch the great-circle arc on the globe.
How to use the calculator
- 1Enter the origin airport
Type the city name, the airport name, or the three-letter IATA code. The autocomplete searches across all three fields and prioritises exact IATA matches.
- 2Enter the destination airport
Repeat the search for the arrival airport. The 3D globe updates as soon as both endpoints are selected so you can preview the great- circle path before computing.
- 3Pick a cabin class
Economy is the default — the CO₂ figure scales by the DESNZ cabin multipliers (1.0 × economy through 4.0 × first). You can change this later without recomputing the geometry.
- 4Calculate and review
The results page returns distance in three units, block time, CO₂e by class, bearing, jet-lag estimate, fuel, and the animated globe. Every figure links back to the formula on /methodology.
Limitations and disclaimer
AirMilesCalc provides decision-support estimates, not flight plans or regulated disclosures. Distances are geodesic great-circle paths; actual flown paths bend around airspace and oceanic tracks; individual flights diverge from fleet-average emission factors. The seven important caveats are consolidated below.
| Number | Limit | Typical magnitude |
|---|---|---|
| Flight distance | Great-circle path, not flown path | Actual ≈ 1–4 % longer due to ATC / winds |
| Block time | Still-air, no jet stream modelled | ±10 % typical, ±60 min on transatlantic |
| CO₂e per cabin | DESNZ fleet-weighted UK average | Individual flight may differ ±20 % |
| Cabin multipliers | Allocated by floor area, not measurement | Convention, not physics |
| Airport coordinates | OpenFlights community-maintained snapshot | Periodic, not live |
| Route table | OpenFlights routes.dat, June 2014 final feed | Topology only, not current schedule |
| Jet-lag recovery | Population mean from Sack 2010 | Individual variation 0.5 × – 2 × |