During the past two years, several continuous high grade centrifugals have been installed in the Australian sugar industry. Kirby et al. (1990) have demonstrated the excellent performance obtained for the NQEA Superfugal. It is clear that continuous machines will ultimately replace many high grade batch installations. In high grade applications, the specific duty being proposed for the machine strongly influences the capacity of the machine. The performance varies with massecuite properties, the sugar purity target and with machine design and operating parameters. For instance, the Superfugal might produce 50 tonne/h of JA sugar from an A massecuite but might only produce 15 tonne/h of VHP sugar from a difficult B massecuite. Also how does one compare the performances of different machines? This paper proposes guidelines to help answer these questions.