Flight CO₂ calculator
To or from the UK and most of Europe, Turkey or North Africa.
Use the great-circle (straight-line) distance — DESNZ's factors already add 8% for indirect routing and holding.
Flights from London Heathrow
Return trips, per passenger, on DESNZ's 2026 factors with radiative forcing (the without-RF figure is for comparison). London to New York and back in economy is 1.30 tonnes CO₂e.
| To | Distance (km) | Economy | Business | Economy, no RF |
|---|---|---|---|---|
| Edinburgh * | 534 | 0.24 t | — | 0.14 t |
| Dublin | 449 | 0.11 t | 0.17 t | 0.07 t |
| Amsterdam | 370 | 0.09 t | 0.14 t | 0.06 t |
| Paris Charles de Gaulle | 348 | 0.09 t | 0.13 t | 0.05 t |
| Barcelona | 1,148 | 0.29 t | 0.43 t | 0.17 t |
| Malaga | 1,676 | 0.42 t | 0.63 t | 0.25 t |
| Faro | 1,713 | 0.43 t | 0.65 t | 0.25 t |
| Tenerife South | 2,932 | 0.74 t | 1.11 t | 0.44 t |
| Rome Fiumicino | 1,444 | 0.36 t | 0.54 t | 0.21 t |
| Athens | 2,427 | 0.61 t | 0.92 t | 0.36 t |
| Istanbul | 2,487 | 0.63 t | 0.94 t | 0.37 t |
| Dubai | 5,498 | 1.29 t | 3.73 t | 0.76 t |
| New York JFK | 5,540 | 1.30 t | 3.76 t | 0.77 t |
| Orlando | 6,965 | 1.63 t | 4.73 t | 0.96 t |
| Los Angeles | 8,760 | 2.05 t | 5.95 t | 1.21 t |
| Delhi | 6,731 | 1.58 t | 4.57 t | 0.93 t |
| Bangkok | 9,578 | 2.24 t | 6.50 t | 1.33 t |
| Singapore | 10,883 | 2.55 t | 7.39 t | 1.51 t |
| Sydney | 17,021 | 3.98 t | 11.55 t | 2.36 t |
Great-circle distance from Heathrow. * Domestic flights have one DESNZ factor for every seat, so there is no economy or business split; the figure shown is the average passenger.
DESNZ 2026 flight factors
kg CO₂e per passenger km, with radiative forcing (and without, in brackets).
| Cabin | Domestic | Short-haul | Long-haul | International |
|---|---|---|---|---|
| Average passenger | 0.22928 (0.13552) | 0.12786 (0.07559) | 0.15282 (0.09043) | 0.14253 (0.08420) |
| Economy | — | 0.12576 (0.07435) | 0.11704 (0.06926) | 0.10916 (0.06449) |
| Premium economy | — | — | 0.18726 (0.11081) | 0.17465 (0.10318) |
| Business | — | 0.18863 (0.11152) | 0.33940 (0.20083) | 0.31656 (0.18701) |
| First | — | — | 0.46814 (0.27701) | 0.43663 (0.25794) |
From the government's Greenhouse gas reporting: conversion factors 2026, Business travel — air (flat file revised 31 July 2026). DESNZ sets the band by country, not distance, in its haul definition table: domestic is within the UK (with the Channel Islands and the Isle of Man); short-haul is to or from the UK and most of Europe, Turkey or North Africa (Egypt, Morocco, Tunisia, Algeria, Libya); long-haul is to or from the UK and anywhere else — Israel, Ukraine, Russia, Moldova and Cape Verde included; international is between two non-UK airports. — means DESNZ publishes no factor for that cabin; the calculator uses the nearest it does publish (economy for short-haul premium economy, business for short-haul first, the average passenger for domestic) and says so.
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How the figure is worked out
The great-circle distance between the two airports, times DESNZ's factor for that kind of flight and that cabin, per passenger. DESNZ's factors already include 8% extra distance for the way planes really fly — around restricted airspace, holding to land — so they apply to the straight-line distance. For the average passenger, domestic flights carry the highest factor per kilometre (0.22928 kg with radiative forcing, against 0.15282 long-haul), because take-off and climb burn a large share of a short flight's fuel — though a long-haul business or first-class seat is higher still.
Radiative forcing
As well as CO₂, planes release water vapour, contrails and nitrogen oxides high in the atmosphere, which add to the warming. DESNZ allows for it by adding 70% to the CO₂ in its "with RF" factors, and says organisations should include it to capture the full climate impact of their flying — while noting the science on its size is still uncertain. Untick it in the calculator for the direct emissions alone.
Why business class counts for more
The factors share a flight's emissions out by the floor space each seat takes. A long-haul business seat (0.33940 kg CO₂e per passenger km) carries 2.9× the emissions of an economy seat (0.11704), and first 4.0×. When you don't know the class, DESNZ's average-passenger factor covers the mix.
Source: DESNZ, Greenhouse gas reporting: conversion factors 2026 (flat file revised 31 July 2026) — Business travel – air, and its haul definition by country; airport positions from OurAirports.
Related reading
Frequently asked questions
How much CO₂ is a flight from London to New York?
About 1.30 tonnes CO₂e per passenger for a return trip in economy on DESNZ's 2026 factors, including radiative forcing (0.77 t without it). In business class it's about 3.76 t.
Should I include radiative forcing?
DESNZ says organisations should, to capture the full climate impact of flying, and the calculator includes it by default. It adds 70% to the CO₂; the science on its exact size is still developing, so whichever you choose, use it consistently from year to year.
Does class of travel matter?
A lot. Seats are charged by the space they take, so on long-haul a business seat is 2.9 times economy and first 4.0 times.
What distance should I use?
The great-circle (shortest) distance between the airports — the calculator works it out from their positions. DESNZ’s factors already include its 8% uplift for indirect routing, so adding it again would count it twice.
Is a domestic flight worse per mile?
Yes. DESNZ's domestic factor is 0.22928 kg CO₂e per passenger km with radiative forcing, against 0.15282 for an average long-haul passenger, because take-off and climb are a bigger share of a short trip.