El càlcul és a partir de les fonts que apareixen més avall.
Dades extretes del documental Cowspiracy http://www.cowspiracy.com/facts
Land required to feed 1 person for 1 year:
Vegan: 1/6th acre
Vegetarian: 3x as much as a vegan
Meat Eater: 18x as much as a vegan [xvii]
Robbins, John. Diet for a New America, StillPoint Publishing, 1987, p. 352
On average, one acre of land of any level of fertility will be able to produce 15 to 18 times more protein from plant based sources than from animal products. Additionally, using any agricultural database regionally, nationally, or internationally, one can calculate that on average between 10 times and 100 times (in weight) more plant foods (vegetables, fruit, grain/nuts) on one acre of land than from animal products raised on that same acre of land, regardless of the level of fertility of that particular acre of land, presuming it is the same acre used for either product, animal or plant based.