The calculation of carbon food prints, food miles and food prints is part of what we do. Knowledge of this helps to keep us critically aware about the workings of our food systems. We use these calculations, for example, to study the impact of local food. The studies show that logistics and transportation have a major impact on the footprint from local food. A spin-off from our work is the Internet tool Urban Food Print where you can estimate how many hectares are needed to feed a set number of people. The model also works the other way: you can calculate how many people can be fed using a specific area. The model demonstrates a simplified picture of reality, therefore, the results are only an approximation. Even so, it gives a good estimate of the number of people that can be kept nourished by a specific area.