Note: This is one answer among dozens of answers. You can search this answer for yourself and see all the answers. No one knows for sure how many they have, and the number increases every year.
I estimated from what I heard a while back that they ay have up to 12 nukes. But if they have more that makes them a more dangerous adversary for any nation that goes against them. Most of the reports on North Korea's abilities always hinge on their ability to launch a missile from their own soil. They seldom ever mention having shorter range missiles launched from subs, or ships, or snuck into a target country for detonation. The other unknown is how many nukes they have sold to other nations like Iran, Saudi Arabia, Turkey Pakistan, Vietnam, Ukraine, South Africa, Brazil, Argentina, Indonesia and a host of terrorist groups like ISIS? Then there is the question of chemical and biological warfare. How much do they have and how much have they developed for other countries and terrorists? Once a nation goes rogue and hates the majority of the world there seems to be no limit to what they will come up with to sell secretly for large amounts of money. Since the nation of North Korea is so poor and limited in resources and manufacturing it is obvious that they have gone to selling any weapons and drugs to bring in an income.
By 2016, North Korea is projected to have 14 to 48 nuclear weapon equivalents. (For uranium weapons, each weapon is assumed to contain 20 kilograms of weapon-grade uranium.)
North Korea and weapons of mass destruction - Wikipedia ...