Environment & fromAtoB

Environment & fromAtoB

That's how we calculate the CO₂ emissions

Environment & fromAtoB

The world of travel is exciting. It allows us to explore this beautiful planet, discover different cultures, taste worldwide cuisines, and experience local traditions.

While we all treasure the unforgettable moments of traveling, we must admit traveling produces exceptionally harmful greenhouse gases. By making greener decisions, we can minimize our environmental impact while continuing to enjoy the beauty of traveling.

Evaluate all your travel options

Bus or train, flight or rideshare? Every mode of transport has a different CO₂ footprint. We want you to be well informed when booking your next trip: that’s why we now not only show you the price, travel time and stopovers but also the CO₂ emission of your journey.

We understand that flying is one of the least environmentally friendly ways to travel, yet, even among flights, you can find greener unicorns! Also, you may find routes to some of your destinations more accessible by ground transport. Being informed is the key! With our new CO₂ label and sorting feature, you are now able to find the least environmentally harmful ways to get to your destination and back!


How do we calculate the emission


We analyse the CO₂ emission per type of transport (For more detailed information, check out the FAQ section below.)


We created our own algorithm. It calculates the CO₂ emissions based on several factors, such as length of the route, the number of stop-overs, the max quantity of travelers and other green gases contributing to the negative impact.


We label the individual results based on the number of kilograms of CO₂ they emit so you can make better informed decisions.

Frequently asked questions

How do we calculate the CO₂ emission for each route?

When calculating the CO₂ emission of your journey, we mainly consider 2 parameters: the distance travelled and the means of transport. To determine the distance travelled, we are using the great-circle distance (the shortest distance between two points on the surface of a sphere) and then multiply it by 1,3. You can learn more about the sources we use to calculate the CO₂ emission for the respective means of transport in the questions below.

Why are there „green“ and „brown“ CO₂ search results?

Our current, first version of the CO₂ calculator divides all search results in 2 groups depending on their CO₂ emission − the half with the lower CO₂ emission is marked green, the other half is marked brown. This enables you to see at one glance whether the CO₂ emission of your connection is below or above average.

How do we calculate the CO₂ emission of trains?

According on the data of UmweltMobilChecks as well as the data of IFEU(Institut für Energie- und Umweltforschung Heidelberg GmbH), we calculate the CO₂ emission based on a value of 22 g CO₂ per km and person for long-distance connections (more than 50 km) and 60 g CO₂ for short-distance traffic (less than 10 km). The CO₂ emission of distances between 10 and 50 km is determined by a mixed calculation. In our first version of the CO₂ calculator, this data applies for Deutsche Bahn as well as all other rail transport providers. We apologize for any small deviations, we are currently working on a more detailed representation of the respective providers.

How do we calculate the CO₂ emission of buses?

We calculate the CO₂ emission for buses based on data from Flixbus (24 g of CO₂ per km and person).

How do we calculate the CO₂ emission of flights?

We calculate the CO₂ emission of flights based on data of myclimate.org and IFEU (Institut für Energie- und Umweltforschung Heidelberg GmbH), factoring in the distance of the flight, the average number of seats in the aircraft, the average occupancy rate, the average cargo load as well as other greenhouse gases than CO₂.

How do we calculate the CO₂ emission of rideshares?

To determine the CO₂ emission for rideshares, we combine the data of Blablacar with this calculator, assuming the journey is unterhaken in an average medium-sized car. At the present time, we are not yet able to adapt our search results to a specific vehicle type. Regarding the occupancy rate, we assume there are 3-4 travelers in a car (according to Blablacar, a car carries 3,9 passengers on average during journeys within Germany, and a slightly lower number during journeys within Europe). This results in an average CO₂ emission of 50 g CO₂ per km and person. Please note: The average occupancy rate is independent of the fact whether you are searching a rideshare for one person or several people.

What does fromAtoB do to help the environment?

Being sustainable is at the core of our company. We love enjoying the beautiful views from the train, meeting interesting people on a bus, biking to work or marching the streets with Greta for a greener future!

Intro picture

We stay up-to-date on all matters of sustainability, we participate in and lead initiatives to influence political and local infrastructure positively and, let’s not forget, we are fanatic recycling warriors!

Never miss another ticket bargain

Our newsletter provides you with the latest ticket bargains, tips and news. We protect your e-mail address and you can unsubscribe from the newsletter at any time.