The term "TNT equivalence" is a normalization technique for equating properties of an explosive to TNT, the standard. There are many ways to calculate "TNT equivalence" and the term is often misused because the property in question and basis for the equivalence are not defined.
This worksheet is primarily designed to assist mining companies in determining if they should submit form 9-4040-A to the U.S. Geological Survey. This form is part of the U.S. implementation of the Comprehensive Test Ban Treaty and is submitted voluntarily by mines that conduct blasts with over 300 short tons "TNT equivalent" of explosives.
This worksheet uses the property of energy called the heat of combustion or heat of explosion and is expressed in units of kilocalories per gram. This is one of the more common types of "TNT equivalence" and is the one used on USGS form 9-4040A.