Online GHG Calculators are web-based applications that will calculate CO2 emissions based on some type of activity, such as an amount of electricity used or kilometres driven. These tools are a fun way to get familiar with the concept of a personal carbon footprint. However they are absolutely inadequate for calculating real GHG emission levels for the purposes of GHG reporting, project accounting and assertion. This is because in most cases, these calculators only consider CO2 emissions and not other GHGs. Therefore the end result is not usually expressed in CO2 equivalent (CO2e). Also by using an online GHG calculator, the ISO 14064 principles of transparency and data quality are not satisfied because it will be difficult for a validator or verifier to establish the exact calculation algorithms used for such calculations.
In conclusion, while GHG calculators are great fun and useful for educational proposes, they are not suitable for GHG accounting purposes. The list of links on this site is therefore for educational purposes only.