Fragmentation size distribution of a blast is the primordial KPI that determines the quality of a blast. Many variables such as blasting geometrical parameters, rock properties, explosive specification and in-situ geology influence rock fragmentation. It is difficult to give complete theoretical solution for its prediction. However, empirical models for the estimation of size distribution of rock fragments have been developed. A blast fragmentation model, based on the Kuz-Ram fragmentation model, has been developed to predict the entire fragmentation size distribution, taking into account intact and joints rock properties, the type and properties of explosives and the drilling pattern. Results produced by this method are often compared with real fragmentation data obtained from a blast quarry.