TNT equivalent is a method of quantifying the energy released in explosions. The "ton of TNT" is a unit of energy equal to 4.184 gigajoules, which is approximately the amount of energy released in the detonation of a metric ton (1,000 kilograms or 1 megagram) of TNT. The "megaton of TNT" is a unit of energy equal to 4.184 petajoules.