The report describes an interactive computer program, written to estimate the capital and operating expenses of electrostatic precipitators, fabric filters, and venturi scrubbers used on coal-fired boilers. The program accepts as input the current interest rate, coal analysis, emission limit, and design and operating parameters of the control device. The installed cost of the collector and the annual fixed and variable operating and maintenance costs are estimated. Based on the interest rate specified, an annual payment of interest and principal is calculated for the amount of capital required. This annual capital cost is added to the annual operating and maintenance costs to yield a total annual cost of the collector. A comparison between reported and predicted costs indicates that the model is capable of +/-25 percent accuracy.