The Energy Efficiency Design Index for International Shipping (EEDI) is a metric that quantifies a vessel's carbon emissions per unit of transport work, typically measured in grams of CO₂ per tonne-nautical mile. EEDI serves as a standardized measure to evaluate the energy efficiency of ships, playing a critical role in promoting sustainable maritime operations and reducing environmental impact.

Fuel consumption (FC) measured in metric tonnes (tonnes) refers to the quantity of fuel used by a vessel, typically expressed in metric tonnes, providing a standardized measure to evaluate fuel usage over a given period or distance. This metric is crucial for assessing the operational efficiency and environmental impact of maritime transport.

Carbon emissions (CE) measured in metric tonnes (tonnes) refer to the total amount of carbon dioxide (CO₂) released into the atmosphere as a result of fuel combustion, quantified in units of metric tonnes for standardization and comparative analysis, essential for assessing environmental impact and regulatory compliance.