Just off the top of my head and knowing there are many exceptions, American workers generally get two days off (weekends) every week. That's 104 days off a year.
We get about 9 paid holidays, and roughly two more weeks of paid vacation (more if you stay at a company longer). That's another 19 days off, or about 123 days off a year. 123 is about a third of 365, so working Americans get about 1/3rd of the days of the year off (34%).
If Europeans get 6 weeks off, that's an additional 20 days off, or 143 days off a year (39%).
Now if you assume the average person works 8 hours a day and is awake 16 hours a day, then the numbers double. So Americans get 64% of all waking hours off from work, and Europeans 78% off.