In order to accurately reflect the cost estimates of lift-force Wave Energy Converters (WECs), a parametric cost model is developed. The definition, establishment and description of the parametric cost model is the purpose of the present article. The parameters of the cost model include the costs of developing and consenting, of the wave energy converter, of the balance of plant, of the installation and commissioning, and of decommissioning. To carry out the initial techno-economic analysis, the widely used parameters Capital Expenditures (CAPEX) and Operational Expenditures (OPEX) will be utilised and an economic modelling framework is suggested to carry out the assessment. For this purpose, the parametric cost model will be incorporated in the Danish COE Calculation Tool, which is a transparent and simple Excel-based software, free-to-download, that since 2014 has assisted many users in estimating the cost of energy of a wave energy device when operating at different locations. A description of the added capabilities and updates of the Tool will also be described in the article. Lastly, an example of the application of the Tool to three different configurations of the LiftWEC concept, where the parametric cost model is used, is presented.