What is a Man-Year?

A man-year is a measure of how much work one person does in a calendar year.

How Does a Man-Year Work?

For example, let's say the Facilities Maintenance Department of the University of XYZ bills the other departments of the university for the time it spends fixing, repairing, replacing, or responding to maintenance requests. Last year, it billed these departments for 30,000 hours of work. If the Facilities Maintenance Department expects to bill out at least that many hours next year, how many full-time employees will it need?

The real question here is how many man-years are in 30,000 hours. Given that a full-time employee works 40 hours per week for 52 weeks, a full-time person will work (40 x 52 = 2,080) hours in a year. If we divide 30,000 by 2,080, we see that the Facilities Maintenance Department must have at least 14 full-time people.

Why Does a Man-Year Matter?

The man-year metric doesn't just help companies plan overhead; it helps them measure overhead per person, productivity per person, and various other types of performance even if some employees are part-time, temporary or seasonal.