Rail grinding has become an important maintenance activity over the past three decades and the importance of rail grinding is likely to augment owing to future demands in rail transport sector particularly for heavy haul lines. The preventive grinding strategy is preferred over the corrective grinding strategy by most rail infrastructure owners, as it can maintain the rails economically by targeting the magic wear rate. Grinding decisions on when to grind (Grinding intervals), how much to grind (Material removal) and where to grind do not have a strong economic insight in the current practice. Impact of these grinding decisions on the total rail maintenance cost is not researched extensively. This paper will discuss the various factors that influence the grinding decision. An economical model is proposed which can be used as a support to rail grinding teams for an informed grinding decision.