Salaried workers use an average of just two-thirds of their allotted holidays per year, a survey shows.

The survey of 952 employed workers released Monday by job portal Job Korea found that workers get an average of 12.2 holidays a year, but they generally take only 8.4 days off.

Some 65.6 percent of respondents said they are not free to take holidays at will. Asked why, the largest number or 35.1 percent cited a heavy workload, followed by company atmosphere (34.7 percent) and worries about their superiors (20.8 percent).