American workers are spending hours doing nothing, and it is costing their companies more than $100 billion a year, a new study says.

Employers are paying that much in wages for “idle time”—periods when employees are on the clock but unable to get any work done, according to research to soon be published in the Journal of Applied Psychology.

The problem crosses industries and occupations, ranging from an investment banker who can’t finish a PowerPoint presentation because she is waiting for data from a colleague to a store cashier without customers to check out. More than three-quarters of the 1,003 workers surveyed across 29 occupational categories said they experience idle time at work, while nearly 22% said it happens daily.

To reach the $100 billion figure, researchers multiplied the average yearly idle time by the number of Americans who work full-time outside of their homes by the median U.S. wage of $17.09 an hour. They said the survey was representative of the American workforce in terms of regions, gender, age, race, education and other factors.

In theory, downtime at work has benefits. Workers are free if an unexpected task pops up, said Andrew Brodsky, an author of the paper and assistant professor at the University of Texas at Austin’s McCombs School of Business. Further, true work breaks help workers recharge and protect against burnout.