Convert million btu to kilotonne TNT

The tonne of TNT is defined as 4.184 GJ, about the energy released by detonating a tonne of the explosive, and is the unit of nuclear yields and of large explosions and impacts. The Hiroshima bomb was about 15 kt, the largest weapon ever tested (Tsar Bomba, 1961) 50 Mt, the 2020 Beirut explosion roughly 0.5 kt, and the Chicxulub impact that ended the dinosaurs on the order of 100 million Mt.

The British thermal unit, the heat that warms a pound of water by one degree Fahrenheit (1,055 J), is now mostly an American unit. US gas bills are in therms of 100,000 Btu (29.3 kWh), wholesale gas is priced per million Btu (MMBtu), and national energy statistics are in quads, 10¹⁵ Btu: the US uses about 100 quads a year. The ton-hour is the cooling delivered by one refrigeration ton over an hour, 12,000 Btu.