In the Southern United States, a rising number of biomass facilities have created new market opportunities for forest landowners, consulting foresters, and loggers, which could increase the competition between the biomass market and pulpwood market for forest biomass. Thus, comparing the profits from conventional roundwood harvesting and biomass harvesting within a range of procurement distances could be crucial to make a harvest decision. In this study, we considered two harvesting systems: conventional and biomass. We developed a decision support tool to predict and compare the final stumpage value from both harvesting systems based on the stand and site conditions, market conditions, and distance to the nearest market. We grew (simulated) loblolly pine (Pinus taeda) plantations to six different thinning ages (12, 14, 16, 18, 20, and 22 yr) at five different site indices (17, 20, 23, 26, and 29 m at a base age of 25 yr) using the PTAEDA4.0 software. Different models were fitted and evaluated for certain training and validating criteria. In both harvesting systems, we select the cube root-transformed model as the best model. Using the models, we predict that the utilization of logging residues and pulpwood as wood chips may yield a higher return to the landowner when the delivered price of the wood chips is comparable to the delivered price of the pulpwood and within the same procurement distance. The selected models thus serve as a decision support tool to inform stakeholders to further maximize their economic return from timber harvesting operations by selecting the most profitable option.