Full-time equivalent (FTE) is a way to measure a worker's productivity and/or involvement in a project. An FTE of 1.0 means that the person is equivalent to a full-time worker. An FTE of 0.5 may signal that the worker is only half-time, or that his projected output (due to differences in qualification, for example) is only half of what one may expect. Typically, different scales are used to calibrate this number, depending on the type of institution (schools, industry, research) and scope of the report (personnel cost, productivity). A professional certification, trade certification, or professional designation often called simply certification or qualification is a designation earned by a person to certify that he is qualified to perform a job. ... Calibration is the determination, by measurement or comparison with a standard, of the correct value of each reading on a measuring instrument. ...

In the U.S. Federal government, FTE is defined by the Government Accountability Office (GAO) as the number of total hours worked divided by the maximum number of compensable hours in a work year as defined by law. For example, if the work year is defined as 2,080 hours, then one worker occupying a paid full time job all year would consume one FTE. Two employees working for 1,040 hours each would consume one FTE between the two of them.

The U.S. Office of Management and Budget, or OMB, the President's budget office, will often place upper limits on the total number of FTE that a given agency may utilize each year. In the past, if agencies were given a ceiling on the actual number of employed workers, which was reported on a given day of the year, the agency could employ more than this number for much of the year. Then, as the reporting deadline approached, employees could be let go to reduce the total number to the authorized ceiling on the reporting date. Providing agencies with a FTE ceiling, which is calculated based on the total number of hours worked by all employees throughout the year, irrespective of the total numbers employed at any point in time, prevents agencies from using such a strategy.

Although the generally accepted human-resources meaning for the "E" in FTE is "equivalent", the term is often overloaded in colloquial usage to indicate a "direct, as opposed to contract, full-time employee". As in "Jane is an FTE, whereas Ralph is a contractor". So Jane is a regular employee, and Ralph works only under contract, perhaps only with irregularity.