Flight Emissions Tracker

Current estimate

{{ perPassengerDisplay }} per passenger | {{ totalDistanceDisplay }}

{{ cabin_class }} {{ passengersCount }} passenger{{ passengersCount === 1 ? '' : 's' }} {{ tripTypeLabel }} RF x{{ rfFactorLabel }} SAF {{ saf_percent }}%

Loading global airport data...

Add a distance in km after each leg to bypass lookup.

Route legs:

Use one leg per line: JFK-LHR, LHR-SIN 10800, or SFO-HND 5124 mi.

Trip type:

Choose One-way for listed legs only, or Round trip to double the full itinerary.

Cabin class:

Economy is baseline; premium, business, and first apply larger cabin multipliers.

Travelers:

Enter whole passengers; minimum is 1.

people

Radiative forcing:

On reports CO2e with the RF multiplier; Off reports direct CO2 only.

RF multiplier: x{{ rfFactorLabel }}

Accepted range: 1.00-3.00 in 0.05 steps.

SAF share: {{ saf_percent }}%

Accepted range: 0-100%; the model assumes 70% savings on the selected share.

Offset price:

Enter USD per tonne CO2e, such as 25; use 0 to omit offset budgeting.

$ / t CO2e

Airport data:

#	From	To	Distance (km)	CO2/pax (kg)	CO2e/pax (kg)	Total CO2e (kg)	Copy
{{ leg.idx }}	{{ leg.fromLabel }}	{{ leg.toLabel }}	{{ leg.distanceLabel }}	{{ leg.co2Label }}	{{ leg.co2eLabel }}	{{ leg.totalCo2eLabel }}

Metric	Value	Copy
{{ row.label }}	{{ row.value }}

Step	Applied value	Audit note	Copy
{{ row.step }}	{{ row.value }}	{{ row.note }}

Embed:

Customize

Include current inputs

Size

Advanced

Width

Height

Aspect ratio

Max height

Collapsible embed

Allow fullscreen

Referrer policy

Sandbox tokens

Air travel emissions are often estimated from an itinerary before aircraft-specific fuel data is available. The activity unit is passenger-kilometers: how far one passenger is carried after route distance, seat allocation, and trip direction are settled. That makes the result useful for comparing travel choices, preparing a rough internal travel budget, or explaining why a long-haul premium-cabin trip can dominate a small travel footprint.

Direct CO2 and CO2e answer different questions. Direct CO2 is tied to jet fuel combustion and is the clearest part of aviation climate accounting. CO2e, or carbon dioxide equivalent, can broaden the estimate with a radiative forcing scenario for high-altitude effects such as contrails, nitrogen oxides, water vapor, soot, and aerosols. Those effects are real, but their size changes with altitude, weather, latitude, time of day, and flight path, so an RF multiplier is best read as an assumption to document, not a universal truth.

Passenger flight emissions estimates start with route distance, then apply seat share and scenario assumptions before reporting CO2e.

The distance source has a large effect on repeatability. Airport coordinates usually produce a great-circle distance, the shortest surface path between two points on Earth. Actual operated flights can be longer because of airways, winds, congestion, taxiing, holding, weather, and air traffic control. A manual distance is more defensible when the estimate must match a booked itinerary, an airline statement, a corporate spreadsheet, or a previous reporting method.

Several assumptions can change the answer without changing the route. Cabin class changes the share of aircraft space assigned to the passenger. Sustainable aviation fuel, or SAF, changes a lifecycle scenario, not the physical distance flown. Offset pricing converts tonnes of CO2e into a budget line, but it does not reduce the emissions estimate itself.

Flight emissions terms and practical cautions
Term	What it represents	Common caution
Passenger-kilometer	One passenger carried one kilometer.	It is a planning unit, not a fuel receipt.
Cabin allocation	A larger seat-space share for premium cabins.	Different methods can use different cabin multipliers.
SAF scenario	A selected sustainable aviation fuel share and assumed lifecycle saving.	It does not prove that fuel was used on a specific aircraft.
Offset cost	A budget based on tonnes of CO2e and a price per tonne.	It changes cost, not the calculated emissions total.

The strongest comparisons hold the accounting assumptions steady. If cabin class, passenger count, trip type, SAF share, RF setting, and offset price stay fixed, differences mostly come from route distance and the haul-band factor applied to each leg.

How to Use This Tool:

Start with the route, then review assumptions before trusting the totals.

Enter Route legs with one leg per line. Use two three-letter IATA codes such as JFK-LHR, or add a manual distance such as LHR-SIN 10800 or SFO-HND 5124 mi.
Keep flight numbers, dates, and unrelated numbers out of Route legs. A number on a route line is treated as the manual distance for that leg.
Set Trip type. One-way counts the listed legs once, while Round trip doubles each resolved leg and marks the leg distance with x2.
Choose Cabin class and enter Travelers. Cabin class changes the per-passenger estimate; traveler count scales the final group totals.
Open Advanced when you need scenario controls. Radiative forcing turns the RF multiplier on or off, SAF share applies the fixed SAF savings assumption, and Offset price sets the cost per tonne CO2e.
Check the warning area and Airport data status. If a leg is ignored or distance lookup fails, replace the line with two valid airport codes or enter a manual distance.
Read Trip totals for the reporting figures, Leg breakdown for the largest route contributors, and Method Ledger for the exact assumptions applied.
Use Leg CO2e bars to spot uneven multi-leg itineraries, then use the JSON view only after the visible warnings and assumptions match the scenario you intend to keep.

Interpreting Results:

Total CO2e is the headline scenario total for all travelers and all counted legs. CO2e/passenger is better for comparing one traveler's share, while Total base CO2 and Base CO2/passenger show the direct-CO2 estimate before the RF multiplier changes it.

Total distance includes the trip multiplier. A 5540 km route entered as Round trip contributes 11080 km to the trip summary, and the emissions total is doubled the same way. In Leg breakdown, the distance cell keeps the original leg distance and adds the multiplier marker.

A larger Total CO2e is not always a route problem. Switching from economy to business, turning RF on, increasing the RF multiplier, reducing SAF share, adding travelers, or changing to round trip can raise the result even when the airport pair is unchanged. Use Method Ledger to verify the applied value before comparing two runs.

Haul-band boundaries can create counterintuitive changes. A leg at exactly 1500 km uses the short-haul factor, while 1501 km uses the medium-haul factor. Treat a small difference near 1500 km or 3500 km as a modeling boundary first, then recheck the distance source.

Technical Details:

Passenger flight-emissions accounting can be built from aircraft fuel burn, load factor, passenger and cargo allocation, cabin configuration, and route-specific operating data. This calculator uses a simpler deterministic model. Each resolved leg receives a distance, the distance selects one of three fixed passenger-kilometer factors, and the result is adjusted by cabin class, SAF share, RF multiplier, travelers, and trip type.

Airport-code lookup uses coordinates from a public airport registry and applies a great-circle calculation with an Earth radius of 6371 km. Great-circle distance is repeatable and easy to audit, but it does not include actual track miles, operational delays, taxiing, or rerouting. Manual distances bypass coordinate lookup and are converted from miles to kilometers with 1 mi = 1.60934 km.

Formula Core:

The total CO2e equation sums each counted leg after the selected distance, factor, cabin, SAF, RF, passenger, and trip assumptions are applied.

E_{total} = \sum_{i = 1}^{n} (d_{i} \times f_{i} \times c \times m_{SAF} \times r \times p \times t)

m_{SAF} = 1 - 0.70 \times \frac{s}{100}

Flight emissions formula symbol meanings
Symbol	Meaning	Unit or value
`d`	Leg distance after lookup or manual entry	km
`f`	Haul-band emissions factor	kg CO2 per passenger-km
`c`	Cabin multiplier	1.00 to 2.40
`s`	SAF share	0% to 100%
`r`	RF multiplier, or `1` when RF is off	1.00 to 3.00
`p`	Traveler count	whole people, minimum 1
`t`	Trip multiplier	1 for one-way, 2 for round trip

For a one-passenger round trip entered as JFK-LHR 5540 in economy with RF 1.90 and SAF 0%, the one-way base calculation is 5540 x 0.115 x 1.00 = 637.10 kg CO2. Multiplying by RF and the round-trip factor gives 637.10 x 1.90 x 2 = 2420.98 kg CO2e.

Offset cost is calculated from the final CO2e total in tonnes. It does not subtract from Total CO2e.

O = \frac{E_{total}}{1000} \times P_{tonne}

Factors and Boundaries:

Distance factors and cabin multipliers used in flight emissions calculations
Assumption	Condition	Applied value
Short-haul factor	`distance <= 1500 km`	0.158 kg CO2/passenger-km
Medium-haul factor	`1500 km < distance <= 3500 km`	0.139 kg CO2/passenger-km
Long-haul factor	`distance > 3500 km`	0.115 kg CO2/passenger-km
Economy cabin	Baseline seat-space assumption	1.00
Premium economy cabin	Raised seat-space assumption	1.26
Business cabin	Raised seat-space assumption	1.54
First cabin	Raised seat-space assumption	2.40

Validation and Output Rules:

Flight emissions input validation and result rules
Area	Rule	Result effect
Route lines	Each non-empty line needs at least two three-letter code groups.	Malformed lines are ignored and reported in the warning area.
Manual distance	A numeric distance on the route line overrides airport-coordinate lookup.	Use `mi` for miles; otherwise the number is treated as kilometers.
SAF share	`0%` to `100%`, with fixed `70%` lifecycle savings on the selected share.	Reduces direct CO2 before RF, passengers, and trip type are applied.
RF multiplier	Off equals `1`; on clamps the multiplier from `1.00` to `3.00`.	Changes Total CO2e, not Total base CO2.
Travelers	Values below `1` are calculated as one traveler.	Group totals scale after the per-passenger leg estimate is calculated.
Offset price	USD per tonne CO2e; `0` leaves no offset budget.	Changes only Estimated offset cost.

Because the factors are fixed, results are most defensible for like-for-like comparison. Official inventories and airline disclosures may use aircraft type, actual fuel burn, load factor, cargo allocation, certified SAF claims, upstream fuel treatment, and jurisdiction-specific reporting rules.

Accuracy Notes:

The result is a scenario estimate for planning, comparison, and rough budgeting. It should not be presented as measured emissions from an operated flight or as verified offset compliance.

Great-circle distance omits taxiing, holding, wind, rerouting, aircraft type, payload, and actual flight plan.
The airport registry can be incomplete, stale, or unavailable; manual distance is the recovery path when lookup fails.
RF captures a selected non-CO2 scenario, not a per-flight contrail or NOx measurement.
SAF share uses one fixed lifecycle-savings assumption and does not verify fuel procurement, book-and-claim accounting, or aircraft fuel loading.
Route text is calculated in the browser and is not sent to a separate emissions service, but the page loads an external airport registry and charting resource.

Advanced Tips:

Use manual distances when a prior report, booking platform, or airline statement must be reproduced. A number on a route line overrides airport-coordinate lookup, so keep unrelated numbers off the leg text.
Compare RF-on and RF-off runs as different accounting scenarios. The Method Ledger records the multiplier so the chosen CO2e treatment is visible later.
Change SAF share only when you want a lifecycle-savings scenario. The calculation assumes a fixed 70% saving on the selected share and does not verify procurement or fuel loading.
Use Leg CO2e bars before trimming a multi-city itinerary. The largest contributor may be a long connection leg rather than the headline origin and destination.
Keep Offset price at 0 when you only need emissions. A positive price adds the budget estimate without changing Total CO2e.
When a leg sits close to 1500 km or 3500 km, test the distance source before interpreting a small change as a real travel-efficiency difference.

Worked Examples:

Round-trip transatlantic estimate

Enter JFK-LHR 5540, choose Round trip, keep Economy, set Travelers to 1, leave RF at 1.90, keep SAF at 0%, and use $25 per tonne. The long-haul factor gives Base CO2/passenger of 637.10 kg for the one-way leg. RF raises one-way CO2e/passenger to 1210.49 kg, and round trip makes Total CO2e about 2420.98 kg. Estimated offset cost is about $60.52.

Boundary check near 1500 km

Enter LHR-MAD 1500, set Trip type to One-way, keep economy, set travelers to 1, and turn RF off. The 1500 km distance remains in the short-haul band, so Total CO2e is 237.00 kg. Change only the distance to 1501 and the medium-haul factor produces about 208.64 kg. That lower figure is a band-boundary artifact, not proof that a slightly longer flight is physically cleaner.

SAF and RF sensitivity for two travelers

For LHR-SIN 10800, choose Round trip, set Travelers to 2, keep economy, leave RF at 1.90, and set SAF to 30%. The SAF multiplier is 0.79, so direct Base CO2/passenger for the one-way leg is 981.18 kg. RF raises one-way CO2e/passenger to 1864.24 kg, and the two-person round-trip Total CO2e becomes about 7456.97 kg.

Troubleshooting an unresolved leg

A line such as London to Singapore does not provide two three-letter airport codes, so the warning area reports an ignored line. Replacing it with LHR-SIN lets airport lookup try coordinates. If lookup is unavailable or the airport registry lacks a code, LHR-SIN 10800 gives the calculation a distance directly and lets the leg appear in Leg breakdown.

FAQ:

Can I enter a multi-city itinerary?

Yes. Put each leg on its own line, such as JFK-LHR and LHR-SIN 10800. The final totals add every resolved leg after trip type, traveler count, cabin, SAF, and RF settings are applied.

Which route format is safest?

Use two three-letter IATA codes such as JFK-LHR or JFK LHR. Add a manual distance only when you want to override lookup, and keep other numbers off that line.

Why does RF change the same route?

RF multiplies direct CO2 into a CO2e scenario. It does not change distance or Total base CO2, so compare RF-on and RF-off outputs as different accounting choices.

Does SAF share prove the airline used SAF?

No. SAF share applies the fixed 70% lifecycle-savings assumption to the selected share. It is not evidence of airline procurement, a book-and-claim certificate, or fuel loaded onto the aircraft.

Why did a leg disappear from the total?

The warning area explains whether a line was ignored or distance lookup failed. Add two valid airport codes or provide a manual distance so the leg can be counted.

Can I use the offset cost as proof of neutral travel?

No. Estimated offset cost is only the selected price per tonne multiplied by the calculated tonnes of CO2e. Offset quality, retirement, additionality, and verification must be checked outside the calculator.

Glossary:

Passenger-kilometer: One passenger carried one kilometer, used as the base activity unit for the estimate.
CO2: Direct carbon dioxide estimate before radiative forcing is applied.
CO2e: Carbon dioxide equivalent, reported here after the selected RF multiplier is applied.
Radiative forcing: A scenario multiplier for broader aviation climate effects beyond direct CO2.
SAF: Sustainable aviation fuel, represented here as a selected share with a fixed lifecycle-savings assumption.
Great-circle distance: The shortest surface path between two coordinate points on the Earth.
IATA code: A three-letter airport code used to identify route endpoints.
Offset cost: A budget estimate based on final tonnes of CO2e and a chosen price per tonne.

References:

ICAO Carbon Emissions Calculator, International Civil Aviation Organization.
ICAO Carbon Emissions Calculator FAQ, International Civil Aviation Organization.
Passenger CO2 Standard Methodology, International Air Transport Association.
Non-CO2 Emissions & Effects, International Air Transport Association.
Life Cycle Emissions of Aviation Fuels, International Civil Aviation Organization.
Airports JSON Registry, mwgg/Airports repository.