How does Carbonkiller calculate my (company’s) carbon footprint?

The calculations in our CO2 calculator are based on the sources below:

Food

• Milieu Centraal

Electricity & gas

• CO2-emissiefactoren a project by Milieu Centraal, Stichting Stimular, Connekt, SKAO and  Ministerie van Infrastructuur en Waterstaat.

Cars

• Average consumption (Carweek)
• Fuel emission factors (CO2-emission factors)
• Electric cars (ANWB)

Flights

• CO2-emission factors 

Disclaimer: Our calculator excludes many aspects of daily life that lead to the emission of CO2. For instance, there is a significant amount of CO2 emissions involved in the production of all kinds of things we buy, such as clothing. 

If you'd like a more detailed estimate, there are plenty of other websites around. For instance by WWF.