Sustainable Travel International

Select whether your trip is a round trip, one-way, or multi-city flight, the number of people flying, and economy or premium class. 

Then, enter the airport codes between your destinations and click “Calculate”.

The results will show the estimated metric tonnes of CO2 emitted and the cost to offset. 

Purchase offsets

If you want to offset a specific amount of metric tonnes, or offset a particular dollar amount, you can do that, too.

Jet-Set Offset

With Jet-Set Offset, you can sign up to automatically donate one cent per mile to environmental non-profits fighting climate change (your donations are 100% tax-deductible in the US).

After you sign up and create your account, you get to choose amongst their environmental organization partners which one you donate to. 

Sign-up to offset

Cool Effect

Don’t worry about calculating flight mileage and simply offset based on your flight duration: 0-6, 7-9, 10-12, or 13+ hours. Toggle the “# of Trips” to 2 for a round trip.

The results will show the estimated metric tonnes of CO2 emitted and the cost to offset. 

What you pay to offset is 100% tax-deductible in the US, and more than 90% of your donation will go straight toward climate projects.

Offset by flight duration

You can also compensate based on the tonnes of CO2 if you know your trip’s estimated output.

Mini Case Study: What does it cost to offset a round-trip flight between Seattle and Paris?

One reason carbon offsetting can feel overwhelming for travelers is that there are a lot of options, and each option can give you really different results. Let’s consider a round-trip flight from Seattle (SEA) to Paris (CDG). 

• Sustainable Travel International: STI calculates the carbon footprint of an economy flight based on the mileage between SEA and CDG. Their results show 2.24 metric tonnes of CO2 which will cost $35.84 to offset ($16.00/metric tonne).
• Cool Effect: Cool Effect does not base its calculation on airport codes, but rather on ranges of flight times. The flight duration between Paris and Seattle is about 10 hours. Using the ’10-12 hours’ duration bucket, Cool Effect applies a long-haul estimate of 1.89 tonnes of CO2 per leg, so a round-trip flight would generate 3.78 tonnes, and cost $55.26 to offset ($14.62/metric tonne).

The cost to offset similar amounts of carbon can vary due to things like the project type, project location, implementation tactics, research and science behind the project, whether the project is run by a for-profit or not-for-profit company, and the percentage of the cost going to the carbon initiative. Read more about these variables in our blog post.

We encourage travelers to find a donation mechanism that is within their price range and supports projects they truly care about. Most important of all is to avoid “analysis paralysis” – take some action instead of none, and if you find a better way to offset in the future, you can always change how and where you give back to the climate.