The total number of employed and unemployed persons in an economy is called the labor force.
In standard labor statistics, the labor force includes people who are working and people without jobs who are actively seeking work and available to take a job. It does not include everyone of working age: retirees, full-time students, caregivers, and others who are neither working nor looking are generally counted as outside the labor force.
In the United States, the Bureau of Labor Statistics measures these categories through the Current Population Survey. The civilian labor force is drawn from the civilian noninstitutional population age 16 and older. The unemployment rate is calculated by dividing the number of unemployed people by the labor force, not by the entire working-age population.
A common mix-up is confusing the labor force with the population. Someone can be of working age but not part of the labor force if they are not employed and have not searched actively for work recently. The related labor-force participation rate measures the labor force as a percentage of the civilian noninstitutional population.