Kazakhstan
males age 16-49: 2,902,859
females age 16-49: 3,543,467 (2010 est.)
Kenya
males age 16-49: 6,162,904
females age 16-49: 5,904,173 (2010 est.)
Kiribati
males age 16-49: 17,941
females age 16-49: 19,758 (2010 est.)
Korea, North
males age 16-49: 4,127,999
females age 16-49: 4,522,707 (2010 est.)
Korea, South
males age 16-49: 10,929,625
females age 16-49: 10,264,608 (2010 est.)
Kosovo
males age 16-49: 429,645
females age 16-49: 389,071 (2010 est.)
Kuwait
males age 16-49: 979,832
females age 16-49: 539,574 (2010 est.)
Kyrgyzstan
males age 16-49: 1,101,709
females age 16-49: 1,243,904 (2010 est.)
Laos
males age 16-49: 1,056,050
females age 16-49: 1,121,640 (2010 est.)
Latvia
males age 16-49: 406,592
females age 16-49: 456,071 (2010 est.)