In this paper, a method for establishing a support criterion or poverty line is developed based on Engel’s Law and domestic nutritional values. The support criterion is differentiated across rural and urban areas. An important result is that for ۱۹۸۹, people who spend less than ۱۰۸,۰۰۰ Rials annually lie inside the poverty line in urban areas. A further important result is that food should be given to the poor instead of money since the food allowance may not be spent appropriately and may lead to abuse.