一天一美元是聯合國2008年的標準，也算是進步。

The poverty threshold, or poverty line, is the minimum level of income deemed necessary to achieve an adequate standard of living in a given country.^[1] In practice, like the definition of poverty, the official or common understanding of the poverty line is significantly higher in developed countries than in developing countries.^[2][3]

The common international poverty line has in the past been roughly $1 a day.^[4] In 2008, the World Bank came out with a revised figure of $1.25 at 2005 purchasing-power parity (PPP).^[5]

Determining the poverty line is usually done by finding the total cost of all the essential resources that an average human adult consumes in one year.^[6] The largest of these expenses is typically the rent required to live in an apartment, so historically, economists have paid particular attention to the real estate market and housing prices as a strong poverty line affector.

Individual factors are often used to account for various circumstances, such as whether one is a parent, elderly, a child, married, etc. The poverty threshold may be adjusted each year.

The poverty threshold is useful as an economic tool with which to measure such people and consider socioeconomic reforms such as welfare and unemployment insurance^{[citation needed]} to reduce poverty.