Travel / Carbon
Flight Carbon Calculator: Route and Cabin Emissions
Estimate flight emissions from great-circle airport distance and the UK Government's 2026 conversion factors. Compare estimates with and without radiative forcing for a one-way or return journey.
Flight Carbon Calculator: Route and Cabin Emissions: Calculates great-circle distance with the haversine formula and a mean Earth radius of 6371.0088 km. The 2026 Business travel- air factors already contain the 8% routing allowance, so it is counted once. Radiative forcing is an uncertain estimate of additional warming from aviation. Upstream fuel supply is excluded. Runs 100% locally in your browser with zero server file uploads.
- Category
- Home & family tools
- Runs
- In your browser
- Cost
- Free · no sign-up
- Availability
- Ready to use
Runs entirely in your browser
Select an airport from the results.
Select an airport from the results.
Choose the haul category explicitly. Non-UK domestic flights use the international category. For connections, calculate each leg separately.
Choose both airports or enter all four coordinates to calculate.
Airport data: OurAirports (public domain)
UK Government DESNZ/DEFRA 2026 factors · Contains public sector information licensed under the Open Government Licence v3.0.
Factors and licence
UK Government GHG Conversion Factors for Company Reporting, 2026, revised flat-format workbook: Business travel- air and Business travel- land. Contains public sector information licensed under the Open Government Licence v3.0. Source: https://www.gov.uk/government/publications/greenhouse-gas-reporting-conversion-factors-2026
Distance allowance
The 2026 methodology, sections 8.37–8.38, confirms that the published flight factors already include the 8% great-circle uplift. The tool displays that adjusted distance separately and does not multiply emissions by the uplift again.
How to use it
- Search for origin and destination airports, or enter coordinates in decimal degrees.
- Choose the DEFRA haul category, cabin class, passenger count and journey type.
- Read the distance and emissions estimates, or copy the result.
Privacy & limitations
Your inputs stay in your browser. No route data is uploaded.
Related tools
Frequently asked questions
Which year are the factors from?
The calculator uses the exact 2026 UK Government DESNZ/DEFRA factors from the revised flat-format workbook.
How do I choose the haul category?
Domestic means within the UK; short-haul means UK-linked European routes; long-haul means UK-linked routes outside Europe. Flights between non-UK airports use international factors. For connections, calculate each leg separately.
Can I search by airport code?
Yes. Search IATA codes, cities, airport names or country names. The local catalogue loads when you first focus an airport field. You can also enter coordinates. Airport data: OurAirports (public domain).
Does the car comparison include everything?
It divides the flight estimate including radiative forcing by the same year's average petrol-car direct emissions factor. It is an illustration, not a complete lifecycle comparison.
Free tool · runs in your browser · no account required