Kilotonn

Kilotonn is not an officially recognized unit in the International System of Units (SI). It is encountered in some texts as a variant or misspelling of kiloton or kilotonne, a unit used to express explosive yield or energy. When used in that sense, kilotonn would refer to the energy equivalent of 1,000 tons of TNT. In joules, this equals about 4.184 × 10^12 J, or 4.184 terajoules.

The standard terms are kiloton (kt) or kilotonne, typically defined as 1,000 metric tonnes of TNT. In practice, this unit is used in military and explosion physics contexts to describe yields. Larger yields are expressed in megatons (Mt), where 1 Mt equals 1,000,000 tons of TNT (about 4.184 × 10^15 J).

Because the word ton can refer to different measures of mass (short ton, long ton, or metric tonne), precise discussions usually specify tonne TNT (tonne TNT) to avoid ambiguity. In many sources, especially English-language technical writing, the metric tonne of TNT is preferred to ensure consistency.

Examples often cited include the Hiroshima bomb, at about 15 kt, and the Tsar Bomba, about 50 Mt (50,000 kt). These figures illustrate the scale range covered by the kiloton to megaton units, rather than a separate, widely used unit named “kilotonn.”

See also: TNT equivalence, explosive yield, energy units, tonne of TNT.