The aim of our study is to find the most appropriate method for examining the impact of small, extensive livestock/mixed farms on climate change. We would like to describe a self–developed calculation, the application of which requires basic mathematical knowledge. With the method, we get an analysis that can be prepared in a short time, either in the case of real farms or model farms that exist in theory. In order to use it, a detailed description of a farm must be prepared, with the help of a year's work process, annual purchases and the summation of annual production. By drawing conclusions from the obtained results, the farm's GHG emissions can be optimized, and it can also help to find climate–neutral farming methods for the production of animal products.