This tool appraises the technical and operational energy efficiency measures for ships. It is designed to support interested stakeholders in investigating and assessing energy efficiency measures and can serve as an initial screening of applicable and relevant measures for further investigation. It is not intended for decision-making purposes, as this requires a more detailed and case-specific analysis. The tool identifies applicable measures for a chosen ship and compares the cost and benefit of those measures. It allows users to evaluate which measures will have the most effect on energy efficiency and which measures are the most cost-effective.