Energy Efficiency Existing Ship Index (EEXI)
A one-time IMO design-efficiency standard that existing ships must meet, the in-service counterpart of the EEDI for new ships.
- Category
- Regulation and Compliance
- Abbreviation
- EEXI
- In force
- 2023
- Dictionary entry
- EEXI
- Last reviewed
How it works
The Energy Efficiency Existing Ship Index (EEXI) is a technical, design-based measure of a ship’s CO₂ efficiency that existing vessels must satisfy since its entry into force. It is calculated like the Energy Efficiency Design Index (EEDI) for newbuildings and compared against a required value for the ship type and size.
Unlike CII, which is operational and assessed yearly, EEXI is a one-off certification of the ship’s design potential. Many owners meet it by limiting engine power, which also encourages slower steaming.
Where it shows up on The Maritime
Also known as: EEXI, energy efficiency existing ship index.
The short dictionary definition is at Dictionary entry: EEXI. This page is the explainer.
Related terms
Carbon Intensity Indicator (CII)
An IMO operational measure of how much CO₂ a ship emits per unit of transport work, graded A to E each year.
Energy Efficiency Design Index (EEDI)
An IMO design standard that caps the CO₂ emitted per unit of transport capacity for newly built ships.
International Maritime Organization (IMO)
The United Nations agency that sets global rules for ship safety, security and pollution prevention.
Slow Steaming
The practice of sailing deliberately below design speed to cut fuel consumption, emissions and effective fleet supply.
More regulation and compliance terms
A plain-English reference definition: our own explanation of a standard shipping concept, not a licensed source or legal advice. See the full glossary or the broader maritime dictionary.
Last reviewed: .