What emission factors does this calculator use?

The tool uses DEFRA 2023 greenhouse gas conversion factors for flights: Economy 0.15530 kg CO2e/pkm, Premium Economy 0.23295 kg CO2e/pkm, Business 0.42839 kg CO2e/pkm, and First Class 0.61219 kg CO2e/pkm (before RFI). These already include radiative forcing.

What is the Radiative Forcing Index (RFI)?

Aviation has a greater warming effect than ground-level CO2 emissions because contrails, water vapor, and other non-CO2 effects occur at altitude. RFI multiplies the direct CO2 figure to capture this full climate impact. DEFRA 2023 factors already embed a 1.9 RFI multiplier.

Should I enter one-way or round-trip distance?

Enter the one-way distance. For a round trip, simply double the distance or use the round-trip toggle. The calculator shows emissions for the distance you provide.

How accurate is the carbon offset cost estimate?

The offset cost uses a rough global average of $15 USD per tonne of CO2e, which reflects voluntary carbon market prices. Actual offset prices range from $5 to $50+ per tonne depending on project type and quality.

Why does Business class emit so much more than Economy?

Business and First class seats take up significantly more floor space per passenger, meaning each passenger is allocated a larger share of the total aircraft emissions. A Business class seat can emit 2.5–4x more than an Economy seat on the same flight.

Does this include the full life-cycle of the flight?

The calculator covers direct combustion emissions and the high-altitude radiative forcing effect. It does not include aircraft manufacturing or airport infrastructure, which are much smaller contributors to the total footprint.

Flight Carbon Calculator

Name: Flight Carbon Calculator
Availability: InStock
Author: Nham Vu

Enter flight distance, cabin class, and passenger count to instantly calculate your CO2 equivalent emissions using ICAO/DEFRA factors.

Flight Details

Flight Distance

One-way distance between origin and destination.

Round trip (one-way)

Cabin Class

Economy Premium Economy Business First Class

Number of Passengers

Enter your flight details to see CO2 emissions.

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Summary

Enter flight distance, cabin class, and passenger count to instantly calculate your CO2 equivalent emissions using ICAO/DEFRA factors.

How it works

Enter the one-way flight distance in kilometers or miles.
Select the cabin class: Economy, Premium Economy, Business, or First.
Set the number of passengers traveling.
The calculator applies DEFRA 2023 emission factors per passenger-km for each cabin class.
A radiative forcing index (RFI) multiplier of 1.9 is applied to account for the full climate impact of aviation at altitude.
Results display CO2e per passenger, total CO2e, and an indicative carbon offset cost.

Use cases

Estimate the carbon footprint of a business trip before booking.
Compare emissions between Economy and Business class for the same route.
Calculate how much CO2 to offset when planning a vacation.
Report Scope 3 travel emissions for corporate sustainability disclosures.
Educate employees on the climate impact of different cabin classes.
Plan lower-carbon travel by seeing the impact of shorter or longer routes.

Frequently Asked Questions

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Last updated: 2026-05-29 · Reviewed by Nham Vu