A model for calculating crystallization temperature (T_x) of multicomponent metallic glasses is proposed by modifying the Miedema’s model which is used for calculating T_x of binary systems. The calculations were carried out for nearly 900 metallic glasses including 470 binary and 398 ternary alloys. In the present model, the cavity formation energy (ΔH_cavity^for) for multicomponent metallic glasses was theoretically derived on the basis of the Miedema’s model. The equation for expressing the relation between experimental T_x and theoretical ΔH_cavity^for was statistically analyzed by the least-squares method, yielding T_x=4.16×ΔH_cavity^for+318. The binary and ternary systems tend to show different equations between T_x and ΔH_cavity^for. The inherent equation in each system was analyzed as simultaneous achievement of the increase in stability of metallic glasses and decrease in ΔH_cavity^for due to multicomponent alloying. Furthermore, the glass-forming ability was predicted by reduced crystallization temperature instead of reduced glass transition temperature. As a result, it was found that reduced crystallization temperature can be calculated close to reduced glass transition temperature except for Pt-, Pd- and La-based systems. It is of great importance that T_x can be calculated for multicomponent metallic glasses by semi-empirical method.