Summary form only given. A semi-empirical model of a helical magnetocumulative generator (MCG) has been developed with a single adjustable variable (called the characteristic time) that describes the time dependent changes in the output current of these generators. A brief description of this model and the characteristic time will be presented. This model has been used to analyze several helical MCGs including the Mark IX, Flexy-I, EF-3, Ranchito, and Jemez generators and it was found that there is relative good agreement between the calculated and experimental data. Due to its simplicity, speed, and the fact that it appears to be independent of the type of helical generator being modeled and the nature of the load, this model can serve as an initial design code.