More than one in 10 Americans say they plan to take a quarter or less of their vacation days this year, but experts say that's not enough time away.

Even Americans who get paid time off from their jobs generally don't take all of it. But experts say that if you aren't taking advantage of your time off, you may be leaving money on the table and even putting your health at risk. Among Americans who are currently employed, 13% say they plan to take a quarter of their vacation days or fewer this year. That's according to recent poll of nearly 2,600 U.S. adults conducted by Bankrate, which also finds that 4% of Americans aren't planning to take any vacation time at all, even though their employers offer it. "That's too much time to be leaving on the table," Ted Rossman, a credit card analyst for Bankrate, tells CNBC Make It. The average American only took about 54% of their available time off in the previous 12 months, Glassdoor found in 2018.

Time off is a valuable perk

For many American workers, vacation time is paid time off, so if you don't use it, you may be losing out on more than just a day away from the office. For example, If you're earning $40,000 or more a year, those vacation days are usually worth thousands of dollars, Scott Dobroski, community expert at Glassdoor, tells CNBC Make It. In total, Americans gave up 212 million days off in 2017, according to Project: Time Off. That amounts to $62.2 billion in "lost benefits," according to the organization.

And even if they get out of the office, many Americans don't fully leave work behind. Glassdoor found that 29% of employees who took time off say a co-worker contacted them about a job-related matter while they were on vacation. "Technology has enabled us to be on and available to work 24/7," Dobroski says. "You're one finger swipe away from your email inbox while you're sitting on the beach in Hawaii."

Vacations can be good for you

Taking a real break is an important habit. Research shows time off may be good for your health and even boost your productivity at work in the long run. "There's creative, innovative, collaborative benefits when you can actually unplug and rest your mind and get away from work for a week or two," Dobroski says. Not to mention real health benefits. Medical research has found that working long hours could increase the risk of heart disease and an increase risk of stroke. Other studies show that overwork can lead to sleep deprivation, with has been linked to several medical conditions, including diabetes. Whereas taking time to recharge, even if it's just a short vacation, can lead to measurable improvements.

Taking a vacation can be good for your career, too. A German professor of organizational psychology found that vacations can help alleviate burnout, while also making workers more resilient and able to cope with stress. "We know that when people can rest, relax and recharge, there's a ripple effect of benefits in terms of productivity, creativity and collaboration when they return to work," Dobroski says. "Employees are not really realizing that they could perform better and refreshed if they take time off." Making sure that employees are taking adequate time to recharge is also on the shoulders of employers. "It's a two way street," Dobroski says. About a quarter of respondents say they don't get any paid vacation, Bankrate found.

A vacation doesn't have to be a major added expense