Resource assessment plays a crucial role in estimating geothermal projects' potential generating capacity at the early phase while the available information is still limited. This estimation involves a probabilistic method to evaluate the uncertainties arising during the estimate calculation. This study aimed to offer an alternative approach by using the bootstrapping technique in estimating geothermal resources, compare the results from each method, and determine the simplest and practical method to be used in geothermal resource assessment. Bootstrapping technique is a statistical method that resamples a data set repeatedly to obtain new resampled data sets. The obtained data from a process similar to the experimental design (ED) are based on the calculation using the heat-stored method. The results from three methods, namely: Monte Carlo, ED-Monte Carlo, and bootstrapping, were compared to learn the differences from each process. The comparison suggests differences between the three methods utilized; meanwhile, the heat-stored with Monte Carlo simulation method remains the simplest. This study is just an initiation for the bootstrapping technique to be further developed and applied in the other geothermal-related researches, intended that this method could be widely used for other geothermal field applications.