Wood biomass is an important energy resource, which can contribute to reduce the dependence on fossil fuels. The research undertakes the microeconomic approach to estimate the technical availability and operational costs of woody biomass production with a higher level of precision than other models present in the literature, as it considers the entire supply chain of the sustainable management of natural forests. This study introduces a tool, which is applied to estimate supply curves and costs of wood biomass extraction from natural forests in the 7th Region of Chile. The simulation indicates that 531,015 tons/year of wood biomass is available in natural forests of the Region under study, with extraction costs ranging from 24.51 to 56.68 US$/ton, or an average total cost of 40.97 US$/ton. The parametric analysis revealed that the maximum admissible distance to the nearest transport route and the transportation costs are the two most influential variables in the estimation of wood biomass supply and cost. Reducing the admissible distance from 5 km to 1 km reduced the availability of biomass by 80%, while a variation of ±50% of transportation costs translated into ±18.3% variation of total extraction costs.The proposed method can be used to identify the technical-economic potential of wood biomass from natural forests in any commune, province, region, or country; as it has the flexibility to allow tests with multiple scenarios and parameters depending on the specific characteristics of the area to be analysed. Essentially, the purpose of this tool is to serve the assessment processes of the identification of new wood biomass resources, allowing decision makers to increase the potential of sustainable and cost-effective woody biomass for heat and electricity generation, and at the same time reduce greenhouse gas emissions and the dependence on fossil fuels.