No 2. Castle Bravo – 15,000 Kilotons
This hydrogen bomb test took place on Bikini atoll. The yield was 2.5 times greater than expected due to some laboratory error during the making of the bomb. This in turn produced fallouts spreading over more than 160 kilometers, which poisoned the inhabitants of the islands near the test site.
No 1. Tsar Bomba – 57,000 Kilotons
Also known as the King of all Bombs, the Tsar bomba had a massive 57 megaton yield. Interestingly, it was scaled down from 100 megatons due to excessive fallout concerns. It is the single largest nuclear weapon ever detonated.