The measure the federal government uses to calculate the cash income Americans need to satisfy minimum living needs and uses it to determine how many people are poor is called:

poverty thresholds

Explanation:

A poverty thresholds is most popularly known as the poverty limit and it is defined as the minimum income which is considered sufficient enough to sustain the basic human need in any particular country. Thus the federal government of the United States calculate the per capita income of its people in order to calculate the number of poor people and the minimum income of the people to meet their social living.