What percentage of the U.S. male population has beards or facial hair?

I don't know about the entire population, but in the US military the percentage is zero! The U.S. Army and U.S. Marine Corps justify banning beards on the basis of both hygiene and of the necessity for a good seal with gas masks. The U.S. Navy did allow beards for a time in the 1970s and 1980s, following a directive from Chief of Naval Operations Elmo Russell Zumwalt, Jr., but subsequently banned them again. The U.S. Coast Guard allowed beards until 1986, when they were banned by the Commandant, Admiral Paul Yost.

What percentage of the U.S. male population has beards or facial hair?

42%

What percentage of the U.S. male population has beards or facial hair?

about 18%