Systems, methods, and devices for predicting pump performance in a downhole tool are provided. A pump performance predictor may receive inputs and generate outputs that predict the performance of a pump of a pumpout module of a downhole tool. The pump performance predictor may calculate and output a set of first predictions that include, for example, the minimum alternator voltage of a power module used to power the electronics of the pumpout module, the maximum pump flowrate, the pumpout performance, and the achievable formation mobility. The pump performance predictor may also calculate and output a set of second predictions that may include, for example, a pump volume efficiency, a pressure profile in a flowline, the number of strokes to fill a sampling bottle, and the time to fill the sampling bottle.