This paper reviews the data available in the bibliography relative to most important economical factors in an offshore wind farm, including the acquisition/installation of wind turbines and foundations, electrical infrastructure, design and project management, and operation/maintenance. These data are necessary to carry out any profitability analysis, or optimization procedure. In order to establish a common reference, prices have been translated into a unique currency and taken to the present year. Taking into account these considerations, the paper presents an estimation of the different costs as a function of the farm size. Finally, the main cost drivers affecting the capital and operating expenditures are presented and discussed. •This is the first paper in a journal summarizing the costs in offshore wind farms.•A table with different inter-array cables, including electrical characteristics, is also included for the first time in a paper with an overall review of costs.•The big disparity in prices is discussed, and when possible, a relationship between the corresponding cost and the wind farm capacity is provided.•In the presented paper, the sources are exactly identified, including pages where data were found and the price in the original currency.