lb) Length 8 metres (26 ft) Diameter 2.1 metres (6.9 ft) Blast yield 50 megatons of TNT (210 PJ) Design  The tsar was a three-stage Teller–Ulam design hydrogen bomb with a yield of 50 megatons (Mt). [2] This is equivalent to 1,400 times the combined power of the two nuclear explosives used in World War II (