Many Americans, one can argue, work too much. Roughly 40% of employees put in more than 50 hours each week at work, while 20% work over 60.

That's a lot of hours, even if you love your job. Not taking earned vacations -- or working someplace that does not offer paid time off (PTO) -- can lead to poor performance, burnout, and resentment.

Despite that, many Americans don't take their allotted time off, and a depressing amount don't get any, according to a new survey conducted on behalf of Celebrity Cruises. Of the 1,200 adult Americans surveyed, only 750 of them reported getting PTO, and some of them simply choose not to use it.

Two people relax on a beach.

It's important to take time off and for bosses to create a workplace culture where that's encouraged. Image source: Getty Images.

How much PTO is being left on the table?

The workers who get PTO reported a median of 14 days a year. This can vary, but PTO often includes any time away -- sick days and vacation days -- though that's not always the case.

Almost half (47%) of those who get PTO did not use all of it, because PTO includes sick days and personal days at many companies. That means workers have to save some of these days for later in the year and may end up not using them. Sometimes that means they're lost, and in other cases, they roll over into the next year.

"A part of the reason for this PTO negligence may be vacation shaming in the workplace," according to the report. "Colleagues and managers don't always respond well to vacation requests. Employees can fear using their paid time off will put their work relationships and career at risk."

That's a pretty toxic workplace environment that's not really good for the employer or the workers. People need to be able to use that time off to recharge, relax, and think about things other than work. If they don't get it, their performance and attitude will almost certainly suffer.

A chart shows how much time off people left on the table.

Image source: Celebrity Cruises.

Let your people go

As a manager or company owner, it's important to create an environment where your employees feel comfortable taking time off. You also want to have a generous policy that separates planned vacations from sick days or family emergencies.

Encourage your staff members to use their vacation time -- and even mandate it if people don't follow along.

This does not mean all workers get every day off they want. It's important to schedule longer trips and work out things like coverage over major holidays or school breaks. That might require some negotiation, especially at smaller companies, and some workers may not get every day they want.

That's a minor issue compared with creating a culture where employees understand that their boss wants them to take time off. Set an example by taking time off yourself, and work with employees to make sure they do the same.