For determining the energy values of foods and fuels. Has a borosilicate glass calorimeter vessel, combustion chamber, open at the bottom and an integral water jacket open at the top. A heat exchanger of copper tubing is connected at the top of the combustion chamber, and passes through a plastic lid, which is tted with a stout wire stirrer and a hole for a thermometer. Calorimeter vessel on a heat resisting platform provided with a support ring and boss head, oxygen inlet tube and igniter coil mounting which can be raised, lowered or swing aside by external controls.