A system and method for estimating the impact of compressor fouling in a combined cycle power block. The current performance of the combined cycle power block is determined and normalized to one or more reference conditions. A baseline performance of a gas turbine of the combined cycle power block is also determined. A predicted performance of the combined cycle power block is then determined by substituting the baseline performance of the gas turbine for the current performance of the gas turbine. A recoverable impact to the combined cycle power block due to compressor fouling is then determined by subtracting the normalized current performance from the predicted performance and a recoverable impact to the fuel consumption of the combined cycle power block is determined from the recoverable impact.