What IS the most powerful nuclear weapon in the world?

Related to another recent thread on nuclear weapons, I’d like to know: what is the most powerful nuclear weapon in the world?

Who has it? How many kilotons of power does it posses? What kind of range does it have? Does it have a name?

According to the reference below, the largest weapon ever made was a 100 megaton Soviet bomb (Tsar Bomba) and the largest ever tested was a 50 megaton version of this Soviet bomb.


Ultimately, bombs this size don’t make sense because they just annilated such a huge area. Most bomb strategy and study is aimed at making them more efficient and strategic, not bigger. This particular bomb was probably intended just to “shock and awe” the West.

The following reference states that the test was hot enough to cause 3rd degree burns at 100 km and some damage as far away as 1000 km. It resulted in a 64 km high mushroom cloud.

The ruskies Tsar bomba claims a 100 Mt, yes ‘Mt’ not ‘Kt’, warhead which would really spoil an afternoon… Though in the west it is believed that these weapons really only produced a 60 Mt yield - maybe that’s all the Russians produced anyway (I’m sure that was a relief to the researchers).

Russian delivery systems are capable of reaching over 10,000 km, so I would guess this weapon could do just that - though at 27 metric tons, maybe it had a lesser range, also it is likely that it was made more for show than use.

Nuclear weapons, like so many other things, suffer from the law of diminishing returns. A 5MT warhead dropped on downtown Chicago will finish the city pretty well. A 100MT warhead would certainly do more damage but what’s the point when a 5MT warhead will essentially ruin the city for years to come? Better yet drop five, 1MT warheads in a pattern around the city and you might get as good a result as a 100MT warhead (just not as deep of a hole in the ground).

In general warheads have gotten smaller over the years. In the ‘old’ days nukes were made extremely powerful because the delivery systems weren’t all that accurate. If your missile might be five miles off from your target point you wanted a bigger boom to still get the stuff you wanted to get (you also generally fired more than one missile…IIRC Chicago had at least five warheads targeted on it to allow for malfunction and inaccuracy and ensure destruction). Now that missiles are extremely accurate you can get away with a much ‘smaller’ (relatively speaking) warhead.

As a result I don’t think anyone fields a warhead even close to the power of the Tsar Bomb. I’m not sure but I think even 10MT warheads are rare and most warheads will be in the less than 1MT range (that is a vague recollection from some reading I did awhile ago so I certainly might be wrong…and I have zero clue what the Russians might still have sitting in a warehouse or silo somewhere).