The unemployment rate, which measures the number of people out of work and looking for jobs, is a key barometer of the health of an economy. It tends to decrease when the economy is growing, as companies hire more workers, and increase when economic activity slows down.

The BLS calculates the unemployment rate by using a monthly survey to identify those in the civilian labor force, which includes both employed and unemployed individuals. The survey also determines whether people are actively looking for work by determining whether they have made specific efforts to find employment in the past four weeks, including sending out resumes, contacting prospective employers, and searching online job advertisements. The BLS publishes a variety of unemployment rate statistics, from the strict U-1 measure to more inclusive versions such as the U-5 and the U-6 measures.

The official unemployment rate—which the BLS calls the U-3 measure—includes all those considered to be unemployed for 15 weeks or more, plus individuals who have been laid off from permanent jobs but have not yet found new ones and discouraged workers (U-6) who have stopped actively seeking employment due to a lack of job opportunities. In addition to the direct impact of lost wages on individual families, high unemployment rates can have widespread effects on communities, leading to social issues such as a decreased sense of community cohesion and higher poverty levels. This can lead to reliance on government benefits and lost tax revenue for local governments.