If the reactions occurring during crosslinking are exothermic, the crosslinking rate can be related to the heat released during the process. Higher is the number of bonds created, higher is the heat released in the reaction. At the end of the reaction, no more heat will be released. To measure the heat flow differential scanning calorimetry can be used.
Assuming that each bond formed during the crosslinking releases the same amount of energy, the degree of curing, , can be defined as follows:
where  is the heat released up to a certain time ,  is the instantaneous rate of heat and is the total amount of heat released in , when the reaction finishes.
Also in this case the degree of curing goes from zero (no bonds created) to one (no more reactions occur) with a slope that changes in time and has its maximum about at half of the reaction.