The project presented in this report is aimed to develop a calculation tool for the economic evaluation of offshore wind power projects. This tool calculates the LCOE (levelized cost of energy), which is the total price that the electricity producer has to pay per each unit of electric energy produced. This calculation is based in the characteristics of the evaluated power plant, but also in the estimation of the production and the losses. The LCOE can be used to evaluate the viability of projects, its competitiveness in the energy market and to calculate the expected profit of projects. In order to make an accurate tool, all the costs involved in the whole life cycle of offshore wind projects must be taken into account; for this reason the life cycle approach is used considering the costs of each phase of wind projects, from cradle to grave. The project is divided in three main parts: the first part consisting in research on wind technology, costs, economic and energetic aspects, in order to make a mathematical model for the LCOE calculation. The resulting model has been compared to trustworthy data in order to evaluate the accuracy of the calculation. The second part of the project consisted in the programming of the software tool using the model established in the first part. A third part was dedicated to evaluating the economic and environmental impact of the project.