The time your employees spend on drafting fantasy football teams, checking scores, and having post-game water-cooler conversations are going to cost you this year, according to a new report. 

Challenger, Gray & Christmas, a Chicago-based global outplacement consultancy, estimated that U.S. employers will lose more than $13 billion in productivity this season.

The firm "fully acknowledges the absurdity of trying to gauge the level of lost work output resulting from fantasy football," according to a blog post on its website. But Challenger, Gray & Christmas CEO John A. Challenger said it's important to acknowledge the kinds of distractions that today's employees face in the workplace. 

"It used to be that only those with computers at their desk were at risk of Internet-related distractions. Now, access to the Internet through our smartphones and tablets means that anyone can go online from anywhere," Challenger said in a statement.

So how did the firm reach its estimate? The number represents the wages that will be paid to unproductive workers. For example, "If a company is paying someone $20 per hour, and one hour of his or her work time was spent researching players or shuffling rosters, then that is $20 in lost wages," the blog post explained.

The report also incorporated the latests numbers from the Fantasy Sports Trade Association (FSTA) regarding how many people participate in fantasy leagues as well as how much time they spend tending to their virtual team. According to FSTA, 31 million working-age Americans participate in all fantasy sports (not just football). 

FSTA says that participants spend three hours each week managing their team and up to nine hours per week reading or watching something about fantasy sports. Challenger, Gray & Christmas reached its final calculations by assuming that two of those hours take place while employees are on the job.

Despite the fact that $13 billion is a massive number, the cost only represents less than one percent of the $1.5 trillion in wages that will be paid out to workers on private-sector payrolls, according to the Bureau of Labor Statistics. 

And Challenger is by no means suggesting that you ban the competition at your company. That might be the worst way to handle the problem.

"An across-the-board ban on all fantasy football or sports websites is likely to backfire and cause a drop in morale, loyalty and, ironically, productivity," he pointed out. "The end result could be far worse than any loss of productivity caused by an hour or two of team management each week."

What's your policy on whether or not employees can spend time at work on fantasy sports?