The unemployment rate measures the percentage of people without jobs among those who are working-age. It is a key indicator of the health of the economy and its ability to absorb new labor-force participants. The number fluctuates widely across countries, reflecting differences in the labor market structure, including unionization and rigidity of labor-market institutions, such as contracts or regulations. It also varies by the extent to which people are willing to accept part-time work and to wait for full-time jobs to become available. The rate is typically calculated at the national level via labour-force surveys conducted by individual governments or by international organizations, such as the Organisation for Economic Co-operation and Development and the World Bank.

In the United States, the Bureau of Labor Statistics reports several different measures of unemployment. The most commonly reported, the U-3 measure, counts people who have no job and have actively searched for one in the previous four weeks. The more expansive U-6 measure includes all unemployed people and adds those who want a full-time job but have been waiting for one to become available, as well as those who are working part time but would prefer to have a full-time job.

The less comprehensive U-5 measure adds those who have contacted an employer or an employment agency in the past month to request a job, but who were turned down. The broader U-6 measurement also includes those who have been discouraged by the lack of jobs and have dropped out of the labor force entirely.