GHG calculators are tools (interactive web, Excel or other software-based) that are designed for easy use of minimal data to quantify GHG emissions and removals. Their assumptions are usually based on IPCC guidelines. They require the user to enter activity data and some environmental data. Some allow manual entry of emission factors. For a comparison of calculators, see Colomb et al. (2013).
GHG calculators provide an accessible approach for non-specialists to estimate GHG impacts from agriculture because they are inexpensive, rapid and a relatively less knowledge-intensive option than other GHG quantification mitigation alternatives (i.e. in-situ measurement campaigns or process-based models). On the other hand, since the level of uncertainty remains very high (Richards et al. 2016), calculators are mainly recommended to raise awareness and plan action (Colomb et al. 2013).