The widespread implementation of combined heat-and-power (CHP) is especially desirable for Hungary, which is a country poor in fossil-fuel resources yet facing a rising energy demand in the wake of recent political and economic upheavals. However, predicting the economics of prospective CHP plants can be difficult. The evaluation of the worthwhileness of each proposed financial investment requires undertaking several repetitive, tedious calculations. A computer model has been devised to facilitate this task. Using this mathematical model, a pay-back period of less than three years is predicted for the small-scale CHP unit proposed for the Budateteny complex in Budapest.