The nuclear blasts over Hiroshima and Nagasaki, Japan were extraordinarily powerful explosions. Their combined power yielded an equivalent of about 36,000 tons of TNT.
Only sixteen years later, the Soviets designed a bomb 3,000 times more powerful at 100,000,000 tons of TNT. Fearing devastation beyond control, they toned it down a bit and tested the bomb at 50,000,000 of TNT. Till this day, the "Tsar Bomba"is the largest man-made explosion, ever.
The bomb detonated at an altitude of 4,2000 meters. The unprecedented explosion was expected to measure 51.5 megatons. In reality, its power was estimated at between 57 and 58.6 megatons, according to the video below.
About 2,000 nuclear tests and 125,000 weapons were made since the first nuclear detonation on July 16, 1945. This video tracks their evolution.