This study comprises of the computation of instantaneous fuel consumptions as a straight means for the interpretation of combustion-related characteristics of coal. The model relies on the determination of the extent of combustion by the calculated fuel combustion amounts at specific instants in order to examine the oxidation behavior and possible influences governed by any variable of interest. In this context, coal briquettes prepared by varying dimensions with and without a volume constraint were evaluated and instantaneous fuel consumptions corresponding to the determined instants were computed for comparison rather than introducing the model with a single experiment. Thus, the influences imposed by the enlargement of the briquette volume as well as by the variations in the compactness of briquettes on the effectiveness and efficiency of combustion reactions were dealt. The applicability of the model was checked by the trends revealed from the view of reaction kinetics in terms of activation energies. At the end of the study, the results deduced on the grounds of instantaneous fuel consumption values were seen to have been in full confirmation by those related to reaction kinetics, showing the applicability of the model in reflecting the particular cases during a combustion reaction.