A first-principles approach can be used to better understand factory figures and their interrelationships. In examining these, distinction is made between Commercial Cane Sugar (CCS) as used in cane payment, and Pure Obtainable Cane Sugar (POCS) as originally defined. The POCS definition can be used to convert chemical control balance losses to Pool Sugar Index (PSI) equivalent units. The molasses loss expected under the CCS/POCS methodology is discussed including two methods of calculation. These concepts are used in examining the relationship between cane purity, formula expected molasses loss, recovery, and PSI. Using the methods described allows better visualisation of the chemical control balance and PSI outcomes. Relatively simple methods are given for using expressions of PSI equivalent to convert losses to financial figures. The explanations should assist readers in understanding aspects of factory figures, and interrelationships between them that are not always immediately apparent. Appropriate background information is provided to allow readers of differing knowledge levels an opportunity to fully understand the concepts discussed. Equations are shown without simplification to provide clarity on their derivation and the underlying concepts. Key words Chemical control balance, Pool Sugar Index, factory evaluation