Most scientists are not knowledgeable about calorimetry. The purpose of this paper is to assist the novice in calorimetry to select the best calorimeter commercially available for their task. The primary literature is a poor guide for instrument selection. Instrument developments in calorimetry are usually not reported in primary literature and calorimetric measurements are usually done with the calorimeter that is available, not the best instrument for the measurement. A procedure for choosing the best calorimeter for a given task is described. (c) 2006 Elsevier B.V. All rights reserved.